Method and apparatus to csi reporting using multiple antenna panels in advanced wireless communication systems

ABSTRACT

A user equipment (UE) for channel state information (CSI) feedback is provided. The UE comprises a transceiver configured to receive, from a base station (BS), configuration information for the CSI feedback, the configuration information indicating a number of antenna panels (N g ) at the BS and a codebook mode, wherein N g &gt;1 and each of the antenna panels comprises antenna ports with a first polarization (P 1 ) and antenna ports with a second polarization (P 2 ). The UE further comprises a processor operably connected to the transceiver, the processor configured to identify the number of antenna panels (N g ) at the BS, identify a codebook for the CSI feedback based on the codebook mode configured between a first codebook mode and a second codebook mode, and generate the CSI feedback using the identified codebook. The transceiver is further configured to transmit the generated CSI feedback to the BS.

CROSS-REFERENCE TO RELATED APPLICATION(S) AND CLAIM OF PRIORITY

The present application claims priority to U.S. Provisional PatentApplication Ser. No. 62/490,296, filed on Apr. 26, 2017; U.S.Provisional Patent Application Ser. No. 62/492,591, filed on May 1,2017; U.S. Provisional Patent Application Ser. No. 62/535,584, filed onJul. 21, 2017; U.S. Provisional Patent Application Ser. No. 62/539,142,filed on Jul. 31, 2017; U.S. Provisional Patent Application Ser. No.62/548,744, filed on Aug. 22, 2017; and U.S. Provisional PatentApplication Ser. No. 62/547,467, filed on Aug. 18, 2017. The content ofthe above-identified patent documents is incorporated herein byreference.

TECHNICAL FIELD

The present disclosure relates generally to channel state information(CSI) reporting schemes for multiple antenna panels in advanced wirelesscommunication systems.

BACKGROUND

Understanding and correctly estimating the channel in an advancewireless communication system between a user equipment (UE) and an eNodeB (eNB) is important for efficient and effective wireless communication.In order to correctly estimate the channel conditions, the UE may report(e.g., feedback) information about channel measurement, e.g., CSI, tothe eNB. With this information about the channel, the eNB is able toselect appropriate communication parameters to efficiently andeffectively perform wireless data communication with the UE.

SUMMARY

Embodiments of the present disclosure provide methods and apparatusesfor CSI reporting in an advanced wireless communication system.

In one embodiment, a user equipment (UE) for CSI feedback is provided.The UE comprises a transceiver configured to receive, from a basestation (BS), configuration information for the CSI feedback, theconfiguration information indicating a number of antenna panels (N_(g))at the BS and a codebook mode, wherein N_(g)>1 and each of the antennapanels comprises antenna ports with a first polarization (P₁) andantenna ports with a second polarization (P₂). The UE further comprisesa processor operably connected to the transceiver. The processor isconfigured to identify the number of antenna panels (N_(g)) at the BS,identify a codebook for the CSI feedback based on the codebook modeconfigured between a first codebook mode and a second codebook mode, andgenerate the CSI feedback using the identified codebook. The transceiveris further configured to transmit the generated CSI feedback to the BS.The codebook corresponding to the first codebook mode is used togenerate the CSI feedback based on a wideband inter-panel co-phase thatis common for a plurality of subbands configured for the CSI feedback.The codebook corresponding to the second codebook mode is used togenerate the CSI feedback based on at least one of (i) a widebandinter-panel co-phase that is common for the plurality of subbands, and(ii) a subband inter-panel co-phase for each of the plurality ofsubbands.

In another embodiment, a BS is provided. The BS comprises a processorconfigured to generate configuration information for CSI feedback, theconfiguration information indicating a number of antenna panels (N_(g))at the BS and a codebook mode, the codebook mode indicating a codebookfor the CSI feedback and configured between a first codebook mode and asecond codebook mode, wherein N_(g)>1 and each of the antenna panelscomprises antenna ports with a first polarization (P₁) and antenna portswith a second polarization (P₂). The BS further comprises a transceiveroperably connected to the processor. The transceiver is configured totransmit, to a UE, the configuration information and receive the CSIfeedback from the UE generated in accordance with the indicatedcodebook. The codebook corresponding to the first codebook mode is usedto generate the CSI feedback based on a wideband inter-panel co-phasethat is common for a plurality of subbands configured for the CSIfeedback. The codebook corresponding to the second codebook mode is usedto generate the CSI feedback based on at least one of (i) a widebandinter-panel co-phase that is common for the plurality of subbands, and(ii) a subband inter-panel co-phase for each of the plurality ofsubbands.

In yet another embodiment, a method for CSI feedback by a UE isprovided. The method comprises receiving, from a BS, configurationinformation for the CSI feedback, the configuration informationindicating a number of antenna panels (N_(g)) at the BS and a codebookmode, wherein N_(g)>1 and each of the antenna panels comprises antennaports with a first polarization (P₁) and antenna ports with a secondpolarization (P₂), identifying the number of antenna panels (N_(g)) atthe BS, identifying a codebook for the CSI feedback based on thecodebook mode configured between a first codebook mode and a secondcodebook mode, generating the CSI feedback using the identifiedcodebook, and transmitting the generated CSI feedback to the BS. Thecodebook corresponding to the first codebook mode is used to generatethe CSI feedback based on a wideband inter-panel co-phase that is commonfor a plurality of subbands configured for the CSI feedback. Thecodebook corresponding to the second codebook mode is used to generatethe CSI feedback based on at least one of (i) a wideband inter-panelco-phase that is common for the plurality of subbands, and (ii) asubband inter-panel co-phase for each of the plurality of subbands.

Other technical features may be readily apparent to one skilled in theart from the following figures, descriptions, and claims.

Before undertaking the DETAILED DESCRIPTION below, it may beadvantageous to set forth definitions of certain words and phrases usedthroughout this patent document. The term “couple” and its derivativesrefer to any direct or indirect communication between two or moreelements, whether or not those elements are in physical contact with oneanother. The terms “transmit,” “receive,” and “communicate,” as well asderivatives thereof, encompass both direct and indirect communication.The terms “include” and “comprise,” as well as derivatives thereof, meaninclusion without limitation. The term “or” is inclusive, meaningand/or. The phrase “associated with,” as well as derivatives thereof,means to include, be included within, interconnect with, contain, becontained within, connect to or with, couple to or with, be communicablewith, cooperate with, interleave, juxtapose, be proximate to, be boundto or with, have, have a property of, have a relationship to or with, orthe like. The term “controller” means any device, system or part thereofthat controls at least one operation. Such a controller may beimplemented in hardware or a combination of hardware and software and/orfirmware. The functionality associated with any particular controllermay be centralized or distributed, whether locally or remotely. Thephrase “at least one of,” when used with a list of items, means thatdifferent combinations of one or more of the listed items may be used,and only one item in the list may be needed. For example, “at least oneof: A, B, and C” includes any of the following combinations: A, B, C, Aand B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented orsupported by one or more computer programs, each of which is formed fromcomputer readable program code and embodied in a computer readablemedium. The terms “application” and “program” refer to one or morecomputer programs, software components, sets of instructions,procedures, functions, objects, classes, instances, related data, or aportion thereof adapted for implementation in a suitable computerreadable program code. The phrase “computer readable program code”includes any type of computer code, including source code, object code,and executable code. The phrase “computer readable medium” includes anytype of medium capable of being accessed by a computer, such as readonly memory (ROM), random access memory (RAM), a hard disk drive, acompact disc (CD), a digital video disc (DVD), or any other type ofmemory. A “non-transitory” computer readable medium excludes wired,wireless, optical, or other communication links that transporttransitory electrical or other signals. A non-transitory computerreadable medium includes media where data can be permanently stored andmedia where data can be stored and later overwritten, such as arewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughoutthis patent document. Those of ordinary skill in the art shouldunderstand that in many if not most instances, such definitions apply toprior as well as future uses of such defined words and phrases.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure and itsadvantages, reference is now made to the following description taken inconjunction with the accompanying drawings, in which like referencenumerals represent like parts:

FIG. 1 illustrates an example wireless network according to embodimentsof the present disclosure;

FIG. 2 illustrates an example eNB according to embodiments of thepresent disclosure;

FIG. 3 illustrates an example UE according to embodiments of the presentdisclosure;

FIG. 4A illustrates a high-level diagram of an orthogonal frequencydivision multiple access transmit path according to embodiments of thepresent disclosure;

FIG. 4B illustrates a high-level diagram of an orthogonal frequencydivision multiple access receive path according to embodiments of thepresent disclosure;

FIG. 5 illustrates a transmitter block diagram for a PDSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 6 illustrates a receiver block diagram for a PDSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 7 illustrates a transmitter block diagram for a PUSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 8 illustrates a receiver block diagram for a PUSCH in a subframeaccording to embodiments of the present disclosure;

FIG. 9 illustrates an example multiplexing of two slices according toembodiments of the present disclosure;

FIG. 10 illustrates an example antenna blocks according to embodimentsof the present disclosure;

FIG. 11 illustrates an example network configuration according toembodiments of the present disclosure;

FIG. 12 illustrates an example multiple antenna panels according toembodiments of the present disclosure;

FIG. 13 illustrates an example multiple antenna panels with 2 ports perpanel according to embodiments of the present disclosure; and

FIG. 14 illustrates a flowchart of a method for CSI feedback accordingto embodiments of the present disclosure.

DETAILED DESCRIPTION

FIGS. 1 through FIG. 14, discussed below, and the various embodimentsused to describe the principles of the present disclosure in this patentdocument are by way of illustration only and should not be construed inany way to limit the scope of the disclosure. Those skilled in the artwill understand that the principles of the present disclosure may beimplemented in any suitably arranged system or device.

The following documents and standards descriptions are herebyincorporated by reference into the present disclosure as if fully setforth herein: 3GPP TS 36.211 v14.2.0, “E-UTRA, Physical channels andmodulation;” 3GPP TS 36.212 v14.2.0, “E-UTRA, Multiplexing and Channelcoding;” 3GPP TS 36.213 v14.2.0, “E-UTRA, Physical Layer Procedures;”3GPP TS 36.321 v14.2.0, “E-UTRA, Medium Access Control (MAC) protocolspecification;” and 3GPP TS 36.331 v14.2.0, “E-UTRA, Radio ResourceControl (RRC) protocol specification;” 3GPP TR 22.891 v1.2.0.

Aspects, features, and advantages of the disclosure are readily apparentfrom the following detailed description, simply by illustrating a numberof particular embodiments and implementations, including the best modecontemplated for carrying out the disclosure. The disclosure is alsocapable of other and different embodiments, and its several details canbe modified in various obvious respects, all without departing from thespirit and scope of the disclosure. Accordingly, the drawings anddescription are to be regarded as illustrative in nature, and not asrestrictive. The disclosure is illustrated by way of example, and not byway of limitation, in the figures of the accompanying drawings.

In the following, for brevity, both FDD and TDD are considered as theduplex method for both DL and UL signaling.

Although exemplary descriptions and embodiments to follow assumeorthogonal frequency division multiplexing (OFDM) or orthogonalfrequency division multiple access (OFDMA), this disclosure can beextended to other OFDM-based transmission waveforms or multiple accessschemes such as filtered OFDM (F-OFDM).

The present disclosure covers several components which can be used inconjunction or in combination with one another, or can operate asstandalone schemes.

To meet the demand for wireless data traffic having increased sincedeployment of 4G communication systems, efforts have been made todevelop an improved 5G or pre-5G communication system. Therefore, the 5Gor pre-5G communication system is also called a “beyond 4G network” or a“post LTE system.”

The 5G communication system is considered to be implemented in higherfrequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higherdata rates. To decrease propagation loss of the radio waves and increasethe transmission coverage, the beamforming, massive multiple-inputmultiple-output (MIMO), full dimensional MIMO (FD-MIMO), array antenna,an analog beam forming, large scale antenna techniques and the like arediscussed in 5G communication systems.

In addition, in 5G communication systems, development for system networkimprovement is under way based on advanced small cells, cloud radioaccess networks (RANs), ultra-dense networks, device-to-device (D2D)communication, wireless backhaul communication, moving network,cooperative communication, coordinated multi-points (CoMP) transmissionand reception, interference mitigation and cancellation and the like.

In the 5G system, hybrid frequency shift keying and quadrature amplitudemodulation (FQAM) and sliding window superposition coding (SWSC) as anadaptive modulation and coding (AMC) technique, and filter bank multicarrier (FBMC), non-orthogonal multiple access (NOMA), and sparse codemultiple access (SCMA) as an advanced access technology have beendeveloped.

FIGS. 1-4B below describe various embodiments implemented in wirelesscommunications systems and with the use of orthogonal frequency divisionmultiplexing (OFDM) or orthogonal frequency division multiple access(OFDMA) communication techniques. The descriptions of FIGS. 1-3 are notmeant to imply physical or architectural limitations to the manner inwhich different embodiments may be implemented. Different embodiments ofthe present disclosure may be implemented in any suitably-arrangedcommunications system.

FIG. 1 illustrates an example wireless network according to embodimentsof the present disclosure. The embodiment of the wireless network shownin FIG. 1 is for illustration only. Other embodiments of the wirelessnetwork 100 could be used without departing from the scope of thisdisclosure.

As shown in FIG. 1, the wireless network includes an eNB 101, an eNB102, and an eNB 103. The eNB 101 communicates with the eNB 102 and theeNB 103. The eNB 101 also communicates with at least one network 130,such as the Internet, a proprietary Internet Protocol (IP) network, orother data network.

The eNB 102 provides wireless broadband access to the network 130 for afirst plurality of user equipments (UEs) within a coverage area 120 ofthe eNB 102. The first plurality of UEs includes a UE 111, which may belocated in a small business (SB); a UE 112, which may be located in anenterprise (E); a UE 113, which may be located in a WiFi hotspot (HS); aUE 114, which may be located in a first residence (R); a UE 115, whichmay be located in a second residence (R); and a UE 116, which may be amobile device (M), such as a cell phone, a wireless laptop, a wirelessPDA, or the like. The eNB 103 provides wireless broadband access to thenetwork 130 for a second plurality of UEs within a coverage area 125 ofthe eNB 103. The second plurality of UEs includes the UE 115 and the UE116. In some embodiments, one or more of the eNBs 101-103 maycommunicate with each other and with the UEs 111-116 using 5G, LTE,LTE-A, WiMAX, WiFi, or other wireless communication techniques.

Depending on the network type, the term “base station” or “BS” can referto any component (or collection of components) configured to providewireless access to a network, such as transmit point (TP),transmit-receive point (TRP), an enhanced base station (eNodeB or eNB),a 5G base station (gNB), a macrocell, a femtocell, a WiFi access point(AP), or other wirelessly enabled devices. Base stations may providewireless access in accordance with one or more wireless communicationprotocols, e.g., 5G 3GPP new radio interface/access (NR), long termevolution (LTE), LTE advanced (LTE-A), high speed packet access (HSPA),Wi-Fi 802.11a/b/g/n/ac, etc. For the sake of convenience, the terms “BS”and “TRP” are used interchangeably in this patent document to refer tonetwork infrastructure components that provide wireless access to remoteterminals. Also, depending on the network type, the term “userequipment” or “UE” can refer to any component such as “mobile station,”“subscriber station,” “remote terminal,” “wireless terminal,” “receivepoint,” or “user device.” For the sake of convenience, the terms “userequipment” and “UE” are used in this patent document to refer to remotewireless equipment that wirelessly accesses a BS, whether the UE is amobile device (such as a mobile telephone or smartphone) or is normallyconsidered a stationary device (such as a desktop computer or vendingmachine).

Dotted lines show the approximate extents of the coverage areas 120 and125, which are shown as approximately circular for the purposes ofillustration and explanation only. It should be clearly understood thatthe coverage areas associated with eNBs, such as the coverage areas 120and 125, may have other shapes, including irregular shapes, dependingupon the configuration of the eNBs and variations in the radioenvironment associated with natural and man-made obstructions.

As described in more detail below, one or more of the UEs 111-116include circuitry, programing, or a combination thereof, for efficientCSI reporting in an advanced wireless communication system. In certainembodiments, and one or more of the eNBs 101-103 includes circuitry,programing, or a combination thereof, for receiving efficient CSIreporting in an advanced wireless communication system.

Although FIG. 1 illustrates one example of a wireless network, variouschanges may be made to FIG. 1. For example, the wireless network couldinclude any number of eNBs and any number of UEs in any suitablearrangement. Also, the eNB 101 could communicate directly with anynumber of UEs and provide those UEs with wireless broadband access tothe network 130. Similarly, each eNB 102-103 could communicate directlywith the network 130 and provide UEs with direct wireless broadbandaccess to the network 130. Further, the eNBs 101, 102, and/or 103 couldprovide access to other or additional external networks, such asexternal telephone networks or other types of data networks.

FIG. 2 illustrates an example eNB 102 according to embodiments of thepresent disclosure. The embodiment of the eNB 102 illustrated in FIG. 2is for illustration only, and the eNBs 101 and 103 of FIG. 1 could havethe same or similar configuration. However, eNBs come in a wide varietyof configurations, and FIG. 2 does not limit the scope of thisdisclosure to any particular implementation of an eNB.

As shown in FIG. 2, the eNB 102 includes multiple antennas 205 a-205 n,multiple RF transceivers 210 a-210 n, transmit (TX) processing circuitry215, and receive (RX) processing circuitry 220. The eNB 102 alsoincludes a controller/processor 225, a memory 230, and a backhaul ornetwork interface 235.

The RF transceivers 210 a-210 n receive, from the antennas 205 a-205 n,incoming RF signals, such as signals transmitted by UEs in the network100. The RF transceivers 210 a-210 n down-convert the incoming RFsignals to generate IF or baseband signals. The IF or baseband signalsare sent to the RX processing circuitry 220, which generates processedbaseband signals by filtering, decoding, and/or digitizing the basebandor IF signals. The RX processing circuitry 220 transmits the processedbaseband signals to the controller/processor 225 for further processing.

The TX processing circuitry 215 receives analog or digital data (such asvoice data, web data, e-mail, or interactive video game data) from thecontroller/processor 225. The TX processing circuitry 215 encodes,multiplexes, and/or digitizes the outgoing baseband data to generateprocessed baseband or IF signals. The RF transceivers 210 a-210 nreceive the outgoing processed baseband or IF signals from the TXprocessing circuitry 215 and up-converts the baseband or IF signals toRF signals that are transmitted via the antennas 205 a-205 n.

The controller/processor 225 can include one or more processors or otherprocessing devices that control the overall operation of the eNB 102.For example, the controller/processor 225 could control the reception offorward channel signals and the transmission of reverse channel signalsby the RF transceivers 210 a-210 n, the RX processing circuitry 220, andthe TX processing circuitry 215 in accordance with well-knownprinciples. The controller/processor 225 could support additionalfunctions as well, such as more advanced wireless communicationfunctions.

For instance, the controller/processor 225 could support beam forming ordirectional routing operations in which outgoing signals from multipleantennas 205 a-205 n are weighted differently to effectively steer theoutgoing signals in a desired direction. Any of a wide variety of otherfunctions could be supported in the eNB 102 by the controller/processor225.

The controller/processor 225 is also capable of executing programs andother processes resident in the memory 230, such as an OS. Thecontroller/processor 225 can move data into or out of the memory 230 asrequired by an executing process.

The controller/processor 225 is also coupled to the backhaul or networkinterface 235. The backhaul or network interface 235 allows the eNB 102to communicate with other devices or systems over a backhaul connectionor over a network. The interface 235 could support communications overany suitable wired or wireless connection(s). For example, when the eNB102 is implemented as part of a cellular communication system (such asone supporting 5G, LTE, or LTE-A), the interface 235 could allow the eNB102 to communicate with other eNBs over a wired or wireless backhaulconnection. When the eNB 102 is implemented as an access point, theinterface 235 could allow the eNB 102 to communicate over a wired orwireless local area network or over a wired or wireless connection to alarger network (such as the Internet). The interface 235 includes anysuitable structure supporting communications over a wired or wirelessconnection, such as an Ethernet or RF transceiver.

The memory 230 is coupled to the controller/processor 225. Part of thememory 230 could include a RAM, and another part of the memory 230 couldinclude a Flash memory or other ROM.

Although FIG. 2 illustrates one example of eNB 102, various changes maybe made to FIG. 2. For example, the eNB 102 could include any number ofeach component shown in FIG. 2. As a particular example, an access pointcould include a number of interfaces 235, and the controller/processor225 could support routing functions to route data between differentnetwork addresses. As another particular example, while shown asincluding a single instance of TX processing circuitry 215 and a singleinstance of RX processing circuitry 220, the eNB 102 could includemultiple instances of each (such as one per RF transceiver). Also,various components in FIG. 2 could be combined, further subdivided, oromitted and additional components could be added according to particularneeds.

FIG. 3 illustrates an example UE 116 according to embodiments of thepresent disclosure. The embodiment of the UE 116 illustrated in FIG. 3is for illustration only, and the UEs 111-115 of FIG. 1 could have thesame or similar configuration. However, UEs come in a wide variety ofconfigurations, and FIG. 3 does not limit the scope of this disclosureto any particular implementation of a UE.

As shown in FIG. 3, the UE 116 includes an antenna 305, a radiofrequency (RF) transceiver 310, TX processing circuitry 315, amicrophone 320, and receive (RX) processing circuitry 325. The UE 116also includes a speaker 330, a processor 340, an input/output (I/O)interface (IF) 345, a touchscreen 350, a display 355, and a memory 360.The memory 360 includes an operating system (OS) 361 and one or moreapplications 362.

The RF transceiver 310 receives, from the antenna 305, an incoming RFsignal transmitted by an eNB of the network 100. The RF transceiver 310down-converts the incoming RF signal to generate an intermediatefrequency (IF) or baseband signal. The IF or baseband signal is sent tothe RX processing circuitry 325, which generates a processed basebandsignal by filtering, decoding, and/or digitizing the baseband or IFsignal. The RX processing circuitry 325 transmits the processed basebandsignal to the speaker 330 (such as for voice data) or to the processor340 for further processing (such as for web browsing data).

The TX processing circuitry 315 receives analog or digital voice datafrom the microphone 320 or other outgoing baseband data (such as webdata, e-mail, or interactive video game data) from the processor 340.The TX processing circuitry 315 encodes, multiplexes, and/or digitizesthe outgoing baseband data to generate a processed baseband or IFsignal. The RF transceiver 310 receives the outgoing processed basebandor IF signal from the TX processing circuitry 315 and up-converts thebaseband or IF signal to an RF signal that is transmitted via theantenna 305.

The processor 340 can include one or more processors or other processingdevices and execute the OS 361 stored in the memory 360 in order tocontrol the overall operation of the UE 116. For example, the processor340 could control the reception of forward channel signals and thetransmission of reverse channel signals by the RF transceiver 310, theRX processing circuitry 325, and the TX processing circuitry 315 inaccordance with well-known principles. In some embodiments, theprocessor 340 includes at least one microprocessor or microcontroller.

The processor 340 is also capable of executing other processes andprograms resident in the memory 360, such as processes for CSI reportingon PUCCH. The processor 340 can move data into or out of the memory 360as required by an executing process. In some embodiments, the processor340 is configured to execute the applications 362 based on the OS 361 orin response to signals received from eNBs or an operator. The processor340 is also coupled to the I/O interface 345, which provides the UE 116with the ability to connect to other devices, such as laptop computersand handheld computers. The I/O interface 345 is the communication pathbetween these accessories and the processor 340.

The processor 340 is also coupled to the touchscreen 350 and the display355. The operator of the UE 116 can use the touchscreen 350 to enterdata into the UE 116. The display 355 may be a liquid crystal display,light emitting diode display, or other display capable of rendering textand/or at least limited graphics, such as from web sites.

The memory 360 is coupled to the processor 340. Part of the memory 360could include a random access memory (RAM), and another part of thememory 360 could include a Flash memory or other read-only memory (ROM).

Although FIG. 3 illustrates one example of UE 116, various changes maybe made to FIG. 3. For example, various components in FIG. 3 could becombined, further subdivided, or omitted and additional components couldbe added according to particular needs. As a particular example, theprocessor 340 could be divided into multiple processors, such as one ormore central processing units (CPUs) and one or more graphics processingunits (GPUs). Also, while FIG. 3 illustrates the UE 116 configured as amobile telephone or smartphone, UEs could be configured to operate asother types of mobile or stationary devices.

FIG. 4A is a high-level diagram of transmit path circuitry. For example,the transmit path circuitry may be used for an orthogonal frequencydivision multiple access (OFDMA) communication. FIG. 4B is a high-leveldiagram of receive path circuitry. For example, the receive pathcircuitry may be used for an orthogonal frequency division multipleaccess (OFDMA) communication. In FIGS. 4A and 4B, for downlinkcommunication, the transmit path circuitry may be implemented in a basestation (eNB) 102 or a relay station, and the receive path circuitry maybe implemented in a user equipment (e.g. user equipment 116 of FIG. 1).In other examples, for uplink communication, the receive path circuitry450 may be implemented in a base station (e.g. eNB 102 of FIG. 1) or arelay station, and the transmit path circuitry may be implemented in auser equipment (e.g. user equipment 116 of FIG. 1).

Transmit path circuitry comprises channel coding and modulation block405, serial-to-parallel (S-to-P) block 410, Size N Inverse Fast FourierTransform (IFFT) block 415, parallel-to-serial (P-to-S) block 420, addcyclic prefix block 425, and up-converter (UC) 430. Receive pathcircuitry 450 comprises down-converter (DC) 455, remove cyclic prefixblock 460, serial-to-parallel (S-to-P) block 465, Size N Fast FourierTransform (FFT) block 470, parallel-to-serial (P-to-S) block 475, andchannel decoding and demodulation block 480.

At least some of the components in FIGS. 4A 400 and 4B 450 may beimplemented in software, while other components may be implemented byconfigurable hardware or a mixture of software and configurablehardware. In particular, it is noted that the FFT blocks and the IFFTblocks described in this disclosure document may be implemented asconfigurable software algorithms, where the value of Size N may bemodified according to the implementation.

Furthermore, although this disclosure is directed to an embodiment thatimplements the Fast Fourier Transform and the Inverse Fast FourierTransform, this is by way of illustration only and may not be construedto limit the scope of the disclosure. It may be appreciated that in analternate embodiment of the present disclosure, the Fast FourierTransform functions and the Inverse Fast Fourier Transform functions mayeasily be replaced by discrete Fourier transform (DFT) functions andinverse discrete Fourier transform (IDFT) functions, respectively. Itmay be appreciated that for DFT and IDFT functions, the value of the Nvariable may be any integer number (i.e., 1, 4, 3, 4, etc.), while forFFT and IFFT functions, the value of the N variable may be any integernumber that is a power of two (i.e., 1, 2, 4, 8, 16, etc.).

In transmit path circuitry 400, channel coding and modulation block 405receives a set of information bits, applies coding (e.g., LDPC coding)and modulates (e.g., quadrature phase shift keying (QPSK) or quadratureamplitude modulation (QAM)) the input bits to produce a sequence offrequency-domain modulation symbols. Serial-to-parallel block 410converts (i.e., de-multiplexes) the serial modulated symbols to paralleldata to produce N parallel symbol streams where N is the IFFT/FFT sizeused in BS 102 and UE 116. Size N IFFT block 415 then performs an IFFToperation on the N parallel symbol streams to produce time-domain outputsignals. Parallel-to-serial block 420 converts (i.e., multiplexes) theparallel time-domain output symbols from Size N IFFT block 415 toproduce a serial time-domain signal. Add cyclic prefix block 425 theninserts a cyclic prefix to the time-domain signal. Finally, up-converter430 modulates (i.e., up-converts) the output of add cyclic prefix block425 to RF frequency for transmission via a wireless channel. The signalmay also be filtered at baseband before conversion to RF frequency.

The transmitted RF signal arrives at UE 116 after passing through thewireless channel, and reverse operations to those at eNB 102 areperformed. Down-converter 455 down-converts the received signal tobaseband frequency, and remove cyclic prefix block 460 removes thecyclic prefix to produce the serial time-domain baseband signal.Serial-to-parallel block 465 converts the time-domain baseband signal toparallel time-domain signals. Size N FFT block 470 then performs an FFTalgorithm to produce N parallel frequency-domain signals.Parallel-to-serial block 475 converts the parallel frequency-domainsignals to a sequence of modulated data symbols. Channel decoding anddemodulation block 480 demodulates and then decodes the modulatedsymbols to recover the original input data stream.

Each of eNBs 101-103 may implement a transmit path that is analogous totransmitting in the downlink to user equipment 111-116 and may implementa receive path that is analogous to receiving in the uplink from userequipment 111-116 Similarly, each one of user equipment 111-116 mayimplement a transmit path corresponding to the architecture fortransmitting in the uplink to eNBs 101-103 and may implement a receivepath corresponding to the architecture for receiving in the downlinkfrom eNB s 101-103.

5G communication system use cases have been identified and described.Those use cases can be roughly categorized into three different groups.In one example, enhanced mobile broadband (eMBB) is determined to dowith high bits/sec requirement, with less stringent latency andreliability requirements. In another example, ultra reliable and lowlatency (URLL) is determined with less stringent bits/sec requirement.In yet another example, massive machine type communication (mMTC) isdetermined that a number of devices can be as many as 100,000 to 1million per km2, but the reliability/throughput/latency requirementcould be less stringent. This scenario may also involve power efficiencyrequirement as well, in that the battery consumption may be minimized aspossible.

A communication system includes a downlink (DL) that conveys signalsfrom transmission points such as base stations (BSs) or NodeBs to userequipments (UEs) and an Uplink (UL) that conveys signals from UEs toreception points such as NodeBs. A UE, also commonly referred to as aterminal or a mobile station, may be fixed or mobile and may be acellular phone, a personal computer device, or an automated device. AneNodeB, which is generally a fixed station, may also be referred to asan access point or other equivalent terminology. For LTE systems, aNodeB is often referred as an eNodeB.

In a communication system, such as LTE system, DL signals can includedata signals conveying information content, control signals conveying DLcontrol information (DCI), and reference signals (RS) that are alsoknown as pilot signals. An eNodeB transmits data information through aphysical DL shared channel (PDSCH). An eNodeB transmits DCI through aphysical DL control channel (PDCCH) or an Enhanced PDCCH (EPDCCH).

An eNodeB transmits acknowledgement information in response to datatransport block (TB) transmission from a UE in a physical hybrid ARQindicator channel (PHICH). An eNodeB transmits one or more of multipletypes of RS including a UE-common RS (CRS), a channel state informationRS (CSI-RS), or a demodulation RS (DMRS). A CRS is transmitted over a DLsystem bandwidth (BW) and can be used by UEs to obtain a channelestimate to demodulate data or control information or to performmeasurements. To reduce CRS overhead, an eNodeB may transmit a CSI-RSwith a smaller density in the time and/or frequency domain than a CRS.DMRS can be transmitted only in the BW of a respective PDSCH or EPDCCHand a UE can use the DMRS to demodulate data or control information in aPDSCH or an EPDCCH, respectively. A transmission time interval for DLchannels is referred to as a subframe and can have, for example,duration of 1 millisecond.

DL signals also include transmission of a logical channel that carriessystem control information. A BCCH is mapped to either a transportchannel referred to as a broadcast channel (BCH) when the DL signalsconvey a master information block (MIB) or to a DL shared channel(DL-SCH) when the DL signals convey a System Information Block (SIB).Most system information is included in different SIBs that aretransmitted using DL-SCH. A presence of system information on a DL-SCHin a subframe can be indicated by a transmission of a correspondingPDCCH conveying a codeword with a cyclic redundancy check (CRC)scrambled with system information RNTI (SI-RNTI). Alternatively,scheduling information for a SIB transmission can be provided in anearlier SIB and scheduling information for the first SIB (SIB-1) can beprovided by the MIB.

DL resource allocation is performed in a unit of subframe and a group ofphysical resource blocks (PRBs). A transmission BW includes frequencyresource units referred to as resource blocks (RBs). Each RB includesNR_(sc) ^(RB) sub-carriers, or resource elements (REs), such as 12 REs.A unit of one RB over one subframe is referred to as a PRB. A UE can beallocated M_(PDSCH) RBs for a total of m_(sc) ^(PDSCH)·N_(sc) ^(RB)REsfor the PDSCH transmission BW.

UL signals can include data signals conveying data information, controlsignals conveying UL control information (UCI), and UL RS. UL RSincludes DMRS and Sounding RS (SRS). A UE transmits DMRS only in a BW ofa respective PUSCH or PUCCH. An eNodeB can use a DMRS to demodulate datasignals or UCI signals. A UE transmits SRS to provide an eNodeB with anUL CSI. A UE transmits data information or UCI through a respectivephysical UL shared channel (PUSCH) or a Physical UL control channel(PUCCH). If a UE needs to transmit data information and UCI in a same ULsubframe, the UE may multiplex both in a PUSCH. UCI includes HybridAutomatic Repeat request acknowledgement (HARQ-ACK) information,indicating correct (ACK) or incorrect (NACK) detection for a data TB ina PDSCH or absence of a PDCCH detection (DTX), scheduling request (SR)indicating whether a UE has data in the UE's buffer, rank indicator(RI), and channel state information (CSI) enabling an eNodeB to performlink adaptation for PDSCH transmissions to a UE. HARQ-ACK information isalso transmitted by a UE in response to a detection of a PDCCH/EPDCCHindicating a release of semi-persistently scheduled PDSCH.

An UL subframe includes two slots. Each slot includes N_(symt) ^(UL)symbols for transmitting data information, UCI, DMRS, or SRS. Afrequency resource unit of an UL system BW is a RB. A UE is allocatedN_(RB) RBs for a total of N_(sc)·N^(RB) for a transmission BW. For aPUCCH, N_(RB)=1. A last subframe symbol can be used to multiplex SRStransmissions from one or more UEs. A number of subframe symbols thatare available for data/UCl/DMRS transmission is N_(symb)=2·(N_(symb)^(UL)−1)−N_(SRS), where N_(SRS)=1 if a last subframe symbol is used totransmit SRS and N_(SRS)=0 otherwise.

FIG. 5 illustrates a transmitter block diagram 500 for a PDSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the transmitter block diagram 500 illustrated in FIG. 5 isfor illustration only. FIG. 5 does not limit the scope of thisdisclosure to any particular implementation of the transmitter blockdiagram 500.

As shown in FIG. 5, information bits 510 are encoded by encoder 520,such as a turbo encoder, and modulated by modulator 530, for exampleusing quadrature phase shift keying (QPSK) modulation. A serial toparallel (S/P) converter 540 generates M modulation symbols that aresubsequently provided to a mapper 550 to be mapped to REs selected by atransmission BW selection unit 555 for an assigned PDSCH transmissionBW, unit 560 applies an Inverse fast Fourier transform (IFFT), theoutput is then serialized by a parallel to serial (P/S) converter 570 tocreate a time domain signal, filtering is applied by filter 580, and asignal transmitted 590. Additional functionalities, such as datascrambling, cyclic prefix insertion, time windowing, interleaving, andothers are well known in the art and are not shown for brevity.

FIG. 6 illustrates a receiver block diagram 600 for a PDSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the diagram 600 illustrated in FIG. 6 is for illustrationonly. FIG. 6 does not limit the scope of this disclosure to anyparticular implementation of the diagram 600.

As shown in FIG. 6, a received signal 610 is filtered by filter 620, REs630 for an assigned reception BW are selected by BW selector 635, unit640 applies a fast Fourier transform (FFT), and an output is serializedby a parallel-to-serial converter 650. Subsequently, a demodulator 660coherently demodulates data symbols by applying a channel estimateobtained from a DMRS or a CRS (not shown), and a decoder 670, such as aturbo decoder, decodes the demodulated data to provide an estimate ofthe information data bits 680. Additional functionalities such astime-windowing, cyclic prefix removal, de-scrambling, channelestimation, and de-interleaving are not shown for brevity.

FIG. 7 illustrates a transmitter block diagram 700 for a PUSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the block diagram 700 illustrated in FIG. 7 is forillustration only. FIG. 7 does not limit the scope of this disclosure toany particular implementation of the block diagram 700.

As shown in FIG. 7, information data bits 710 are encoded by encoder720, such as a turbo encoder, and modulated by modulator 730. A discreteFourier transform (DFT) unit 740 applies a DFT on the modulated databits, REs 750 corresponding to an assigned PUSCH transmission BW areselected by transmission BW selection unit 755, unit 760 applies an IFFTand, after a cyclic prefix insertion (not shown), filtering is appliedby filter 770 and a signal transmitted 780.

FIG. 8 illustrates a receiver block diagram 800 for a PUSCH in asubframe according to embodiments of the present disclosure. Theembodiment of the block diagram 800 illustrated in FIG. 8 is forillustration only. FIG. 8 does not limit the scope of this disclosure toany particular implementation of the block diagram 800.

As shown in FIG. 8, a received signal 810 is filtered by filter 820.Subsequently, after a cyclic prefix is removed (not shown), unit 830applies a FFT, REs 840 corresponding to an assigned PUSCH reception BWare selected by a reception BW selector 845, unit 850 applies an inverseDFT (IDFT), a demodulator 860 coherently demodulates data symbols byapplying a channel estimate obtained from a DMRS (not shown), a decoder870, such as a turbo decoder, decodes the demodulated data to provide anestimate of the information data bits 880.

In next generation cellular systems, various use cases are envisionedbeyond the capabilities of LTE system. Termed 5G or the fifth generationcellular system, a system capable of operating at sub-6 GHz and above-6GHz (for example, in mmWave regime) becomes one of the requirements. In3GPP TR 22.891, 74 5G use cases has been identified and described; thoseuse cases can be roughly categorized into three different groups. Afirst group is termed ‘enhanced mobile broadband’ (eMBB), targeted tohigh data rate services with less stringent latency and reliabilityrequirements. A second group is termed “ultra-reliable and low latency(URLL)” targeted for applications with less stringent data raterequirements, but less tolerant to latency. A third group is termed“massive MTC (mMTC)” targeted for large number of low-power deviceconnections such as 1 million per km² with less stringent thereliability, data rate, and latency requirements.

In order for the 5G network to support such diverse services withdifferent quality of services (QoS), one method has been identified inLTE specification, called network slicing. To utilize PHY resourcesefficiently and multiplex various slices (with different resourceallocation schemes, numerologies, and scheduling strategies) in DL-SCH,a flexible and self-contained frame or subframe design is utilized.

FIG. 9 illustrates an example multiplexing of two slices 900 accordingto embodiments of the present disclosure. The embodiment of themultiplexing of two slices 900 illustrated in FIG. 9 is for illustrationonly. FIG. 9 does not limit the scope of this disclosure to anyparticular implementation of the multiplexing of two slices 900.

Two exemplary instances of multiplexing two slices within a commonsubframe or frame are depicted in FIG. 9. In these exemplaryembodiments, a slice can be composed of one or two transmissioninstances where one transmission instance includes a control (CTRL)component (e.g., 920 a, 960 a, 960 b, 920 b, or 960 c) and a datacomponent (e.g., 930 a, 970 a, 970 b, 930 b, or 970 c). In embodiment910, the two slices are multiplexed in frequency domain whereas inembodiment 950, the two slices are multiplexed in time domain. These twoslices can be transmitted with different sets of numerology.

LTE specification supports up to 32 CSI-RS antenna ports which enable aneNB to be equipped with a large number of antenna elements (such as 64or 128). In this case, a plurality of antenna elements is mapped ontoone CSI-RS port. For next generation cellular systems such as 5G, themaximum number of CSI-RS ports can either remain the same or increase.

FIG. 10 illustrates an example antenna blocks 1000 according toembodiments of the present disclosure. The embodiment of the antennablocks 1000 illustrated in FIG. 10 is for illustration only. FIG. 10does not limit the scope of this disclosure to any particularimplementation of the antenna blocks 1000.

For mmWave bands, although the number of antenna elements can be largerfor a given form factor, the number of CSI-RS ports—which can correspondto the number of digitally precoded ports—tends to be limited due tohardware constraints (such as the feasibility to install a large numberof ADCs/DACs at mmWave frequencies) as illustrated in FIG. 10. In thiscase, one CSI-RS port is mapped onto a large number of antenna elementswhich can be controlled by a bank of analog phase shifters. One CSI-RSport can then correspond to one sub-array which produces a narrow analogbeam through analog beamforming. This analog beam can be configured tosweep across a wider range of angles by varying the phase shifter bankacross symbols or subframes. The number of sub-arrays (equal to thenumber of RF chains) is the same as the number of CSI-RS portsN_(CSI-PORT). A digital beamforming unit performs a linear combinationacross N_(CSI-PORT) analog beams to further increase precoding gain.While analog beams are wideband (hence not frequency-selective), digitalprecoding can be varied across frequency sub-bands or resource blocks.

FIG. 11 illustrates an example network configuration 1100 according toembodiments of the present disclosure. The embodiment of the networkconfiguration 1100 illustrated in FIG. 11 is for illustration only. FIG.11 does not limit the scope of this disclosure to any particularimplementation of the configuration 1100.

In order for the 5G network to support such diverse services withdifferent quality of services (QoS), one scheme has been identified inLTE specification, called network slicing.

As shown in FIG. 11, An operator's network 1110 includes a number ofradio access network(s) 1120 (RAN(s)) that are associated with networkdevices such as eNBs 1130 a and 1130 b, small cell base stations(femto/pico eNBs or Wi-Fi access points) 1135 a and 1135 b. The network1110 can support various services, each represented as a slice.

In the example, an URLL slice 1140 a serves UEs requiring URLL servicessuch as cars 1145 b, trucks 1145 c, smart watches 1145 a, and smartglasses 1145 d. Two mMTC slices 1150 a and 550 b serve UEs requiringmMTC services such as power meters 555 b, and temperature control box1155 b. One eMBB slice 1160 a serves UEs requiring eMBB services such ascells phones 1165 a, laptops 1165 b, and tablets 1165 c. A deviceconfigured with two slices can also be envisioned.

From LTE specification, MIMO has been identified as an essential featurein order to achieve high system throughput requirements and MIMO maycontinue to be the same in NR. One of the key components of a MIMOtransmission scheme is the accurate CSI acquisition at the eNB (or TRP).For MU-MIMO, in particular, the availability of accurate CSI isnecessary in order to guarantee high MU performance. For TDD systems,the CSI can be acquired using the SRS transmission relying on thechannel reciprocity.

For FDD systems, on the other hand, it can be acquired using the CSI-RStransmission from eNB, and CSI acquisition and feedback from UE. In FDDsystems, the CSI feedback framework is “implicit” in the form ofCQI/PMI/RI derived from a codebook assuming SU transmission from eNB.Because of the inherent SU assumption while deriving CSI, this implicitCSI feedback is inadequate for MU transmission. Since future (e.g. NR)systems are likely to be more MU-centric, this SU-MU CSI mismatch may bea bottleneck in achieving high MU performance gains. Another issue withimplicit feedback is the scalability with larger number of antenna portsat eNB.

For large number of antenna ports, the codebook design for implicitfeedback is quite complicated (for example, in LTE specification, thetotal number of Class A codebooks=44), and the designed codebook is notguaranteed to bring justifiable performance benefits in practicaldeployment scenarios (for example, only a small percentage gain can beshown at the most). Realizing aforementioned issues, it has agreed toprovide specification support to advanced CSI reporting in LTEspecification, which, at the very least, can serve as a good startingpoint to design advanced CSI scheme in NR MIMO. Compared to LTEspecification, the CSI acquisition for NR MIMO may consider thefollowing additional differentiating factors.

In one example of flexibility CSI reporting framework, CSI reporting inNR may be flexible to support users with different CSI reportingcapabilities. For example, some users may only be capable of reportingimplicit CSI in the form of PMI/CQI/RI as in LTE and some other usersmay be capable of reporting both implicit as well as explicit channelreporting. In addition, UE motilities in NR can range from 0 kmph to 500kmph. So, CSI reporting framework may be able to support such diverseuse cases and UE capabilities.

In one example of increased number of antenna ports, in NR MIMO, thenumber of antenna elements at the eNB can be up to 256, which means thatthe total number of antenna ports can be more than 32, which is themaximum number of antenna ports supported in LTE eFD-MIMO. Although thiscan be accommodated with partial-port CSI-RS mapping where each subsetconsists of at most 32 ports, the total number of ports across time canbe extended to a much larger number. As the number of ports increases,meaningful system gain can only be obtained in a MU-centric system.

In one example of increased throughput requirement, the systemthroughput requirements (e.g. for eMBB in NR) is several times more thanthat for LTE eFD-MIMO. Such high throughput requirements can only metwith a mechanism to provide very accurate CSI to the eNB.

In one example of beamforming, following the trend established inFD-MIMO, NR MIMO system may be beam-formed either cell-specifically orUE-specifically, where the beams can either be of analog (RF) or digitalor hybrid type. For such a beam-formed system, a mechanism is needed toobtain accurate beam-forming information at the eNB.

In one example of unified design, since NR includes both above and below6 GHz frequency bands, a unified MIMO framework working for bothfrequency regimes may be preferable.

In the following, for brevity, both FDD and TDD are considered as theduplex method for both DL and UL signaling. Although exemplarydescriptions and embodiments to follow assume orthogonal frequencydivision multiplexing (OFDM) or orthogonal frequency division multipleaccess (OFDMA), the present disclosure can be extended to otherOFDM-based transmission waveforms or multiple access schemes such asfiltered OFDM (F-OFDM).

Depending on the network type, the term “base station” or “BS” can referto any component (or collection of components) configured to providewireless access to a network, such as transmit point (TP),transmit-receive point (TRP), an enhanced base station (eNodeB or eNB),gNB, a macrocell, a femtocell, a WiFi access point (AP), or otherwirelessly enabled devices. Base stations may provide wireless access inaccordance with one or more wireless communication protocols, e.g., 5G3GPP new radio interface/access (NR), long term evolution (LTE), LTEadvanced (LTE-A), high speed packet access (HSPA), Wi-Fi802.11a/b/g/n/ac, etc. For the sake of convenience, the terms “BS” and“TRP” are used interchangeably in this patent document to refer tonetwork infrastructure components that provide wireless access to remoteterminals.

Also, depending on the network type, the term “user equipment” or “UE”can refer to any component such as “mobile station,” “subscriberstation,” “remote terminal,” “wireless terminal,” “receive point,” or“user device.” For the sake of convenience, the terms “user equipment”and “UE” are used in this patent document to refer to remote wirelessequipment that wirelessly accesses a BS, whether the UE is a mobiledevice (such as a mobile telephone or smartphone) or is normallyconsidered a stationary device (such as a desktop computer or vendingmachine).

FIG. 12 illustrates an example multiple antenna panels 1200 according toembodiments of the present disclosure. The embodiment of the multipleantenna panels 1200 illustrated in FIG. 12 is for illustration only.FIG. 12 does not limit the scope of this disclosure to any particularimplementation.

In the following, it is assumed that N₁ and N₂ are the number of antennaports with the same polarization in the first and second dimensions,respectively. For 2D antenna port layouts, it may be N₁>1, N₂>1, and for1D antenna port layouts N₁>1 and N₂=1. So, for a dual-polarized antennaport layout, the total number of antenna ports is 2N₁N₂.

The focus of the present disclosure is on the CSI acquisition for theantenna structure to which multiple antenna panels are applied whereeach panel is a dual-polarized antenna ports with N₁ and N₂ ports in twodimensions. An illustration is shown in FIG. 12 in which there are M=1,2, 4 antenna panels. Furthermore, the antenna pot layout, i.e., (N₁, N₂)value, for each antenna panel is identical.

In one embodiment, a dual-stage codebook: W=W₁W₂ has been proposed forthe multiple antenna panels in which the first stage W₁ codebook is usedto report a beam group comprising L beams, and the second stage W₂codebook is used to report a single beam selection (per layer) from thereported beam group which is common for two polarizations, and aco-phase value selection for the two polarizations, where L beamselection is WB, the single beam selection and co-phase selection is SB.

In one embodiment 1, a UE is configured with W₁ codebook for multipleantenna panels as shown in FIG. 12 with M≥1 panels, which has a blockdiagonal structure with 2M blocks, where the first 2 consecutive blocksare associated with the two polarizations of the 1^(st) antenna panel,the next 2 consecutive blocks are associated with the two polarizationsof the 2^(nd) antenna panel, and so on. The W₁ codebook structure isaccording to at least one of the following two alternatives.

In one example of Alt 1-0 (common for

$\left. W_{1} \right)\;,{W_{1} = \begin{bmatrix}B_{0} & 0 \\0 & B_{0}\end{bmatrix}}$

for M=1 panel,

$W_{1} = \begin{bmatrix}B_{0} & 0 & 0 & 0 \\0 & B_{0} & 0 & 0 \\0 & 0 & B_{0} & 0 \\0 & 0 & 0 & B_{0}\end{bmatrix}$

for M=2 panels and

$W_{1} = \begin{bmatrix}B_{0} & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\0 & B_{0} & 0 & 0 & 0 & 0 & 0 & 0 \\0 & 0 & B_{0} & 0 & 0 & 0 & 0 & 0 \\0 & 0 & 0 & B_{0} & 0 & 0 & 0 & 0 \\0 & 0 & 0 & 0 & B_{0} & 0 & 0 & 0 \\0 & 0 & 0 & 0 & 0 & B_{0} & 0 & 0 \\0 & 0 & 0 & 0 & 0 & 0 & B_{0} & 0 \\0 & 0 & 0 & 0 & 0 & 0 & 0 & B_{0}\end{bmatrix}$

for M=4 panels, where B₀=[b₀, b₁, . . . , b_(L-1)] isa common beam group for all panels comprising L beams.

In one example of Alt 1-1 (per panel W₁),

$W_{1} = \begin{bmatrix}B_{0} & 0 \\0 & B_{0}\end{bmatrix}$

for M=1 panel,

$W_{1} = \begin{bmatrix}B_{0} & 0 & 0 & 0 \\0 & B_{0} & 0 & 0 \\0 & 0 & B_{1} & 0 \\0 & 0 & 0 & B_{1}\end{bmatrix}$

for M=2 panels and

$W_{1} = \begin{bmatrix}B_{0} & 0 & 0 & 0 & 0 & 0 & 0 & 0 \\0 & B_{0} & 0 & 0 & 0 & 0 & 0 & 0 \\0 & 0 & B_{1} & 0 & 0 & 0 & 0 & 0 \\0 & 0 & 0 & B_{1} & 0 & 0 & 0 & 0 \\0 & 0 & 0 & 0 & B_{2} & 0 & 0 & 0 \\0 & 0 & 0 & 0 & 0 & B_{2} & 0 & 0 \\0 & 0 & 0 & 0 & 0 & 0 & B_{3} & 0 \\0 & 0 & 0 & 0 & 0 & 0 & 0 & B_{3}\end{bmatrix}$

for M=4 panels B₀=[b_(0,0), b_(0,1), . . . , b_(0,L-1)], B₁=[b_(1,0),b_(1,1), . . . , b_(1,L-1)], B₂=[b_(2,0), b_(2,1), . . . , b_(2,L-1)]and B₃=[b_(3,0), b_(3,1), . . . , b_(3,L-1)] are beam groups for panels0, 1, 2, and 3, respectively, each comprising L beams.

In one example, only one of the two W₁ codebook structures (Alt 1-0, Alt1-1) is supported in the specification, for example, Alt 1-0. In anotherexample, one of the two structures is configured to the UE via 1-bithigher layer (RRC) or MAC CE based or DCI based signaling. In yetanother example, the UE reports a preferred a W₁ codebook structure as a1-bit WB CSI report either jointly with other WB CSI reports orseparately as a separate WB report. In yet another example, only of thetwo structures is supported for each antenna port layouts and/or Mvalues.

In one embodiment 1A, a UE is configured with W₁ codebook (cf. Alt 1-0or Alt 1-1), where the number of beams (L value) in the beam group foreach panel is the same and is according to at least one of the twoalternatives: Alt 1A-0: L=1; and Alt 1A-1: L=2.

In one example, only one of the two alternatives (Alt 1A-0, Alt 1A-1) issupported in the specification, for example, Alt 1A-0. In anotherexample, one of the two alternatives is configured to the UE via 1-bithigher layer (RRC) or MAC CE based or DCI based signaling. In yetanother example, the UE reports a preferred L value as a 1-bit WB CSIreport either jointly with other WB CSI reports or separately as aseparate WB report. In yet another example, only of the two alternativesis supported for each antenna port layouts and/or M values.

For L=2, at least one of the following is supported for the beam groupstructure or patterns comprising two beams. In one example, only onebeam pattern is supported regardless of the antenna pot layout or (N₁,N₂) values. In one example, only one beam pattern is supported for 2Dantenna port layouts, i.e., (N₁, N₂) with N₁>1 and N₂>1, and only onebeam pattern is supported for 1D antenna port layouts, i.e., (N₁, N₂)with N₁>1 and N₂=1. In one example, two beam patterns are supportedregardless of the antenna pot layout or (N₁, N₂) values. In one example,two beam patterns are supported for 2D antenna port layouts, i.e., (N₁,N₂) with N₁>1 and N₂>1, and one beam pattern is supported for 1D antennaport layouts, i.e., (N₁, N₂) with N₁>1 and N₂=1. In one example, twobeam patterns are supported for 2D antenna port layouts, i.e., (N₁, N₂)with N₁>1 and N₂>1, and two beam patterns are supported for 1D antennaport layouts, i.e., (N₁, N₂) with N₁>1 and N₂=1.

In one embodiment 1B, a UE is configured with W₁ codebook (cf. Alt 1-0or Alt 1-1), where the number of beams (L value) in the beam group foreach panel is the same and is according to at least one of the twoalternatives: Alt 1B-0: L=1; and Alt 1B-1: L=4.

In one example, only one of the two alternatives (Alt 1B-0, Alt 1B-1) issupported in the specification, for example, Alt 1B-0. In anotherexample, one of the two alternatives is configured to the UE via 1-bithigher layer (RRC) or MAC CE based or DCI based signaling. In yetanother example, the UE reports a preferred L value as a 1-bit WB CSIreport either jointly with other WB CSI reports or separately as aseparate WB report. In yet another example, only of the two alternativesis supported for each antenna port layouts and/or M values.

For L=4, at least one of the following is supported for the beam groupstructure or patterns comprising four beams. In one example, only onebeam pattern is supported regardless of the antenna pot layout or (N₁,N₂) values. In one example, only one beam pattern is supported for 2Dantenna port layouts, i.e., (N₁, N₂) with N₁>1 and N₂>1, and only onebeam pattern is supported for 1D antenna port layouts, i.e., (N₁, N₂)with N₁>1 and N₂=1. In one example, two beam patterns are supportedregardless of the antenna pot layout or (N₁, N₂) values. In one example,two beam patterns are supported for 2D antenna port layouts, i.e., (N₁,N₂) with N₁>1 and N₂>1, and one beam pattern is supported for 1D antennaport layouts, i.e., (N₁, N₂) with N₁>1 and N₂=1. In one example, twobeam patterns are supported for 2D antenna port layouts, i.e., (N₁, N₂)with N₁>1 and N₂>1, and two beam patterns are supported for 1D antennaport layouts, i.e., (N₁, N₂) with N₁>1 and N₂=1.

In one embodiment 1C, the W₁ beam groups (B₀, B₁, . . . ) comprises ofoversampled 2D DFT beams. For a given antenna port layout (N1, N2) andoversampling factors (O1, O2) for two dimensions, the DFT beam v_(l,m)can be expressed as follows:

$v_{l,m} = \left\lbrack {\begin{matrix}u_{m} & {e^{j\frac{2\pi \; l}{O_{1}N_{1}}}u_{m}} & \ldots & {\left. {e^{j\frac{2\pi \; {l{({N_{1} - 1})}}}{O_{1}N_{1}}}u_{m}} \right\rbrack^{T}}\end{matrix} {where}{\quad{u_{m} = \left\lbrack \begin{matrix}1 & e^{j\frac{2\pi \; m}{O_{2}N_{2}}} & \ldots & {\left. e^{j\frac{2\pi \; {m{({N_{2} - 1})}}}{O_{2}N_{2}}} \right\rbrack.}\end{matrix} \right.}}} \right.$

In one embodiment 2, a UE is configured with W₂ codebook for M≥1 antennapanels according to at least one of the following alternatives. In oneexample of Alt 2-0 (common intra-panel W₂), W₂=c⊗d or d⊗c where c is anintra-panel W₂ vector (size 2L×1), common for all panels, and d is aninter-panel phase vector (size M×1), where c⊗d denotes the Kroneckerproduct of c and d which is defined as c⊗d=[c₀d c₁d . . . c_(2L-1)d]^(T)where d=[d₀d₁ . . . d_(M−1)].

If W₂=c⊗d, then for M=2: W₂=[c₀d₀c₀d₁ c₁d₀ c₁d₁]^(T). If one of c₀ andd₀ is fixed to 1, one of the two alternate forms for W₂ is considered:W₂=[d₀ d₁ c₁d₀ c₁d₁]^(T); and W₂=[c₀ c₀d₁ c₁ c₁d₁]^(T). If both c₀ andd₀ are fixed to 1, then W₂=[1 d₁ c₁ c₁d₁]^(T).

If W₂=c⊗d, then for M=4: W₂=[C₀d₀ c₀d₁ c₀d₂ c₀d₃ c₁d₀ c₁d₁ c₁d/₂c₁d₃]^(T); since one of c₀ and d₀ can be fixed to 1, one of the twoalternate forms for W₂ is considered: W₂=[d₀ d₁ d₂ d₃ c₁d₀ c₁d₁ c₁d₂c₁d₃]^(T); and W₂=[c₀ c₀d₁ c₀d₂ c₀d₃ c₁ c₁d₁ c₁d₂ c₁d₃]^(T). If both c₀and d₀ are fixed to 1, then W₂=[1 d₁ d₂ d₃ c₁ c₁d₁ c₁d₂ c₁d₁]^(T).

If W₂=d⊗c, then for M=2: W₂=[c₀d₀ c₁d₀ c₀d₁ c₁d₁]^(T); since one of c₀and d₀ can be fixed to 1, one of the two alternate forms for W₂ isconsidered: W₂=[d₀ c₁d₀ d₁ c₁d₁]^(T); and W₂=[c₀ c₁ c₀d₁ c₁d₁]^(T). ForM=4: W₂=[c₀d₀ c₁d₀ c₀d₁ c₁d₁ c₀d₂ c₁d₂ c₀d₃ c₁d₃]^(T); since one of c₀and d₀ can be fixed to 1, one of the two alternate forms for W₂ isconsidered: W₂=[d₀ c₁d₀ d₁ c₁d₁ d₂ c₁d₂ d₃ c₁d₃]^(T); and W₂=[c₀ c₁ c₀d₁c₁d₁ c₀d₂ c₁d₂ c₀d₃ c₁d₃]^(T).

In one example of Alt 2-1 (per panel W₂), W₂=[1 c₁ c₂ c₃ . . .c_(2LM-1)]^(T), where {c_(i)} are independent phase for M panels and 2polarizations. For M=2: W₂=[1 c₁ c₂ c₃]^(T). For M=4: W₂=[1 c₁ c₂ c₃ c₄c₅ c₆ c₇]⁷.

The codebook to report the W₂ phase is at least one of BPSK {1,−1} orQPSK {1,j,−1,−j} or two stage a_(WB)b_(WB) where a_(WB) and a_(SB)codebooks are according to at least one of the following:a_(WB)={1,j,−1,−j} (2 bit WB phase) and a_(SB)={1,j} (1-bit SB phase);a_(WB)={1,j,−1, −j} (2 bit WB phase) and a_(SB)={1, −j} (1-bit SBphase); a_(WB)={1, j, −1, −j} (2 bit WB phase) and

$a_{SB} = \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

(1-bit SB phase);

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

(2 bit WB phase)and

$a_{SB} = \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

(1-bit SB phase);

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

(2 bit WB phase anda_(SB)={1,−j} (1-bit SB phase); and

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

(2 bit WB phase) and a_(SB)={1, j} (1-bit SB phase).

The codebook alternatives for inter-panel phase reporting is accordingto at least one of the following. In one example of Alt 2-0A, a separatecodebook (e.g. W₃) is used to report the inter-panel phase regardless ofwhether the inter-panel phase is reported in a WB or SB manner. Thisalternative is applicable to the case in which the inter-panel phase canbe decoupled from the intra-panel phase. An example of which is Alt 2-0.

In one example of Alt 2-1A, if the inter-panel phase is reported in a WBmanner, then the inter-panel phase is reported jointly with the firstPMI (i₁) indicating beam group using the W₁ codebook.

In one example of Alt 2-2A, if the inter-panel phase is reported in a SBmanner, then the inter-panel phase is reported jointly with the secondPMI (i₂) indicating co-phasing for two polarizations (and beam selectionof L>1) using the W₂ codebook.

In one example of Alt 2-3A, if the inter-panel phase is reporteddifferentially with both WB and SB components, then the WB component ofthe inter-panel phase is reported jointly with the first PMI (i₁)indicating beam group using the W₁ codebook, and the SB component of theinter-panel phase is reported jointly with the second PMI (i₂)indicating co-phasing for two polarizations (and beam selection of L>1)using the W₂ codebook.

One of these alternatives is either fixed in the specification orconfigured via higher layer RRC or dynamic DCI signaling.

In one embodiment 2A, the amplitude is also reported in addition tointer-panel phase according to at least one of the followingalternatives. In one example of Alt 2A-0, the amplitude is reportedindependently for each panel and common for the two polarizations ineach panel. For M panels, M-1 amplitude needs to be reported since theamplitude for the first panel can be assumed to be 1 without loss ofgenerality. In one example of Alt 2A-1, the amplitude is reportedindependently for each panel and for each polarization. For M panels,2M-1 amplitude needs to be reported since the amplitude for the firstpolarization of the first panel can be assumed to be 1 without loss ofgenerality.

The amplitude reporting can either be in a WB manner or in a SB manneror in a differential manner with both WB and SB components. One of thesethree reporting can either be fixed (e.g. WB reporting) or configurablevia higher layer RRC or dynamic DCI signaling. For example, theamplitude reporting can be turned ON or OFF using RRC or dynamic DCIsignaling whereas the phase reporting is always ON.

For N-bit amplitude reporting, the amplitude quantization codebook (WBand/or SB) is according to at least one of the following alternatives.In one example, if N=1, then the amplitude codebook is one of thefollowing: C₀={1, √{square root over (0.5)}}; C₁={1.0}; and C₂={√{squareroot over (1.4125)}, √{square root over (0.7079)}}. In one example, ifN=2, then the amplitude codebook is one of the following: C₀={1,√{square root over (0.5)}, √{square root over (0.25)}, √{square rootover (0.125)}}; and C₁={1, √{square root over (0.5)}, √{square root over(0.25)},}. In one example, if N=3, then the amplitude codebook is one ofthe following: C₀={1, √{square root over (0.5)}, √{square root over(0.25)}, √{square root over (0.125)}, √{square root over (0.0625)},√{square root over (0.0313)}, √{square root over (0.0156)}, √{squareroot over (0.0078)}}; C₁={1, √{square root over (0.5)}, √{square rootover (0.25)}, √{square root over (0.125 )}, √{square root over(0.0625)}, √{square root over (0.0313)}, √{square root over (0.0156)},};and C₂={1, √{square root over (0.6683)}, √{square root over (0.4467)},√{square root over (0.2985)}, √{square root over (0.1995)}, √{squareroot over (0.1334)}, √{square root over (0.0891)}, 0}.

In one embodiment 3, the multi-panel codebook using a modular approachwhere the multi-panel pre-coder vector/matrix W_(MP) is built from thesingle-panel pre-coder vector/matrix W_(SP) as follows. In one exampleof M=2, for rank 1:

$W_{MP} = {\begin{bmatrix}W_{SP} \\{e^{j\; \alpha_{1}}W_{SP}}\end{bmatrix} = {\begin{bmatrix}{W_{1}W_{2}} \\{e^{j\; \alpha_{1}}W_{1}W_{2}}\end{bmatrix} = \begin{bmatrix}v_{1} \\{e^{j\; \beta}v_{1}} \\{e^{j\; \alpha_{1}}v_{1}} \\{e^{j{({\alpha_{1} + \beta})}}v_{1}}\end{bmatrix}}}$

and for rank 2:

$W_{MP} = {\begin{bmatrix}W_{SP} \\{e^{j\; \alpha_{1}}W_{SP}}\end{bmatrix} = {\begin{bmatrix}{W_{1}W_{2}} \\{e^{j\; \alpha_{1}}W_{1}W_{2}}\end{bmatrix} = {\begin{bmatrix}v_{1} & v_{1} \\{e^{j\; \beta}v_{1}} & {{- e^{j\; \beta}}v_{1}} \\{e^{j\; \alpha_{1}}v_{1}} & {e^{j\; \alpha_{1}}v_{1}} \\{e^{j{({\alpha_{1} + \beta})}}v_{1}} & {{- e^{j{({\alpha_{1} + \beta})}}}v_{1}}\end{bmatrix}.}}}$

In one example of M=4, forrank 1:

$W_{MP} = {\begin{bmatrix}W_{SP} \\{e^{j\; \alpha}W_{SP}}\end{bmatrix} = {\begin{bmatrix}{W_{1}W_{2}} \\{e^{j\; \alpha_{1}}W_{1}W_{2}} \\{e^{j\; \alpha_{2}}W_{1}W_{2}} \\{e^{j\; \alpha_{3}}W_{1}W_{2}}\end{bmatrix} = \begin{bmatrix}v_{1} \\{e^{j\; {({\alpha_{1} + \beta})}}v_{1}} \\{e^{j\; {({\alpha_{2} + \beta})}}v_{1}} \\{e^{j{({\alpha_{3} + \beta})}}v_{1}}\end{bmatrix}}}$

and for rank 2:

${W_{MP} = {\begin{bmatrix}W_{SP} \\{e^{j\; \alpha}W_{SP}}\end{bmatrix} = {\begin{bmatrix}{W_{1}W_{2}} \\{e^{j\; \alpha_{1}}W_{1}W_{2}} \\{e^{j\; \alpha_{2}}W_{1}W_{2}} \\{e^{j\; \alpha_{3}}W_{1}W_{2}}\end{bmatrix} = \begin{bmatrix}v_{1} & v_{1} \\{e^{j\; \beta}v_{1}} & {{- e^{j\; \beta}}v_{1}} \\{e^{j\; \alpha_{1}}v_{1}} & {e^{j\; \alpha_{1}}v_{1}} \\{e^{j{({\alpha_{1} + \beta})}}v_{1}} & {{- e^{j{({\alpha_{1} + \beta})}}}v_{1}} \\{e^{j\; \alpha_{2}}v_{1}} & {e^{j\; \alpha_{2}}v_{1}} \\{e^{j{({\alpha_{2} + \beta})}}v_{1}} & {{- e^{j{({\alpha_{2} + \beta})}}}v_{1}} \\{e^{j\; \alpha_{3}}v_{1}} & {e^{j\; \alpha_{3}}v_{1}} \\{e^{j{({\alpha_{3} + \beta})}}v_{1}} & {{- e^{j{({\alpha_{3} + \beta})}}}v_{1}}\end{bmatrix}}}},$

where: v₁ is an oversampled 2D DFT beam; the selection of W_(SP) islimited to be the same for all panels; and the inter-panel phase e^(ja)^(i) (i=1 or 1-3) can be reported either WB or SB or both WB and SB; andthe co-phase e^(jβ)is reported SB.

In one embodiment 4, the UE is configured with a PMI codebook (viahigher layer RRC signaling) for CSI reporting for P=2N₁N₂≥CSI-RS antennaports in M=2 panels as follows: the PMI codebook assumes W=W₁W₂pre-coder structure for rank 1 to 8 (1 layer to 8 layers), where foreach layer W₁=

${W_{1} = \begin{bmatrix}b_{1} & 0 & 0 & 0 \\0 & b_{1} & 0 & 0 \\0 & 0 & b_{1} & 0 \\0 & 0 & 0 & b_{1}\end{bmatrix}},$

b₁ is an oversampled 2D DFT beam; andW₂ performs QPSK co-phasing between panels and polarizations.

The supported combinations of (M, N₁, N₂, O₁, O₂) are tabulated inTABLE 1. The UE is configured with higher-layer parameters (e.g., RRC)multipanel-Config-M, codebook-Config-N1, and codebook-Config-N2, toconfigure the codebook parameters M, N₁ and N₂, respectively. Note thatthere is no need to signal (configure) (O₁,O₂) since only one (O₁,O₂) issupported for each (N₁,N₂). Other alternate tables are shown in TABLES2-5. Note that in TABLE 5, (M, N₁, N₂)=(2, 1, 1) and (4, 1, 1) are alsoconsidered. Since for these two port configurations N1=N₂=1, the W1codebook structure reduces to an M×M identity matrix, there is no W₁feedback needed, i.e., the WB reporting of b₁ is needed (b₁=1). Only oneof these (M, N₁, N₂, O₁, O₂) combination tables (or their anycombinations) is supported in the specification.

TABLE 1 Supported configurations of (O₁, O₂) and (N₁, N₂) Number ofCSI-RS ports (M, N₁, N₂) (O₁, O₂) 8 (2, 2, 1) (4, —) 12 (2, 3, 1) (4, —)16 (2, 2, 2) (4, 4) (2, 4, 1) (4, —) 24 (2, 3, 2), (2, 2, 3) (4, 4) (2,6, 1) (4, —) 32 (2, 4, 2), (2, 2, 4) (4, 4) (2, 8, 1) (4, —)

TABLE 2 Supported configurations of (O₁, O₂) and (N₁, N₂) Number ofCSI-RS ports (M, N₁, N₂) (O₁, O₂) 8 (2, 2, 1) (4, —) 12 (2, 3, 1) (4, —)16 (2, 2, 2) (4, 4) (2, 4, 1) (4, —) 24 (2, 3, 2) (4, 4) (2, 6, 1) (4,—) 32 (2, 4, 2) (4, 4) (2, 8, 1) (4, —)

TABLE 3 Supported configurations of (O₁, O₂) and (N₁, N₂) Number ofCSI-RS ports (M, N₁, N₂) (O₁, O₂) 8 (2, 2, 1) (4, —) 16 (2, 2, 2) (4, 4)(2, 4, 1), (4, 2, 1) (4, —) 24 (2, 3, 2) (4, 4) (2, 6, 1) (4, —) 32 (2,4, 2), (4, 2, 2) (4, 4) (2, 8, 1), (4, 4, 1) (4, —)

TABLE 4 Supported configurations of (O₁, O₂) and (N₁, N₂) Number ofCSI-RS ports (M, N₁, N₂) (O₁, O₂) 8 (2, 2, 1) (4, —) 16 (2, 2, 2) (4, 4)(2, 4, 1), (4, 2, 1) (4, —) 32 (2, 4, 2), (4, 2, 2) (4, 4) (2, 8, 1),(4, 4, 1) (4, —)

TABLE 5 Supported configurations of (O₁, O₂) and (N₁, N₂) Number ofCSI-RS ports (M, N₁, N₂) (O₁, O₂) 4 (2, 1, 1) (—, —) 8 (4, 1, 1) (—, —)(2, 2, 1) (4, —) 16 (2, 2, 2) (4, 4) (2, 4, 1), (4, 2, 1) (4, —) 32 (2,4, 2), (4, 2, 2) (4, 4) (2, 8, 1), (4, 4, 1) (4, —)

If multiple (O₁,O₂) pairs are supported for any (N₁,N₂) pair, then theUE is further configured with higher-layer parameterscodebook-Over-Sampling-RateConfig-O1 andcodebook-Over-Sampling-RateConfig-02, to configure O₁ and O₂,respectively.

The codebook details for rank 1 and rank 2 CSI reporting are as follows.2D DFT beam index (k₁, k₂) may be defined, where k₁=i_(1,1), k₂=i_(1,2).The leading beam index (i_(1,1),i_(1,2)) is reported wideband, wherei_(1,1)=0, 1, . . . N₁O₁−1 and i_(1,2)=0,1, . . . N₂O₂−1, hence itrequires ┌ log₂(N₁O₁N₂O₂)┐ bits.

For 1 layer CSI reporting (rank 1), the pre-coding vector is given by W=

${W = {\frac{1}{\sqrt{MP}}\begin{bmatrix}w_{0,0,0} \\w_{0,1,0} \\w_{1,0,0} \\w_{1,1,0}\end{bmatrix}}},$

and for 2 layer CSI reporting (rank 2), the pre-coding matrix is givenby

${W = {\frac{1}{\sqrt{2{MP}}}\begin{bmatrix}w_{0,0,0} & w_{0,0,1} \\w_{0,1,0} & w_{0,1,1} \\w_{1,0,0} & w_{1,0,1} \\w_{1,1,0} & w_{1,1,1}\end{bmatrix}}},$

where: w_(p,r,l)=b_(k) ₁ _(,k) ₂ ·c_(p,r,l)p=0,1 (for two panels), r=0,1 (for two polarizations), l=0,1 (for two layers); b_(k) ₁ ^(,k) ₂ isan oversampled 2D DFT beam; and c_(p,r,l) is the co-phase value forpanel p, polarization r and layer l.

For rank 1, the reporting of c_(0,1,0), c_(1,0,0,) and c_(1,0,0) areaccording to at least one of the following alternatives. In one exampleof Alt 4-0A, c_(0,0,0)=1, c_(0,1,0) −{1,j,−1,−j}, c_(1,0,0) −{1,j,−1,−j,} and c_(1,1,0) −{1,−j}, where the calculation and reporting ofc_(0,1,0), c_(1,0,0) and c_(1,1,0) can be SB (which requires 6 bits/SB).

In one example of Alt 4-1A, c_(0,0,0)=1, c_(0,1,0) ∈ {1, j,−j},c_(1,0,0) ∈ {1, j, −1, −j} and c_(1,1,0)=c_(0,1,0)×c_(1,0,0), where thecalculation and reporting of c_(0,1,0), c_(1,0,0) and c_(1,1,0) can beSB (which requires 4 bits/SB).

In one example of Alt 4-2A, c_(0,0,0)=1, c_(0,1,0) −{1,j, −1,−j},c_(1,0,0)=a_(1,0,0)b_(1,0,0) and c_(1,1,0)=a_(1,1,0)b_(1,1,0) where

${{a_{1,r,0} \in {\left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\} \mspace{14mu} {and}\mspace{14mu} b_{1,r,0}}} = \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}},$

where the calculation and reporting of c_(0,1,0), b_(1,0,0) andb_(1,1,0) can be SB (which requires 4 bits/SB), and the calculation andreport of a_(1,0,0) and a_(1,1,0) are WB (which requires 4 bits).

In one example of Alt 4-3A, c_(0,0,0)=1, c_(1,0,0) ∈ {1, j, −1,−j},c_(0,1,0)=a_(0,1,0)b_(0,1,0) and c_(1,1,0)=a_(1,1,0)b_(1,1,0) where

${a_{p,1,0} \in {\left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\} \mspace{14mu} {and}\mspace{14mu} b_{p,1,0}} \in \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}},$

where the calculation and reporting of c_(1,0,0), b_(0,1,0) andb_(1,1,0) can be SB (which requires 4 bits/SB), and the calculation andreport of a_(0,1,0) and a_(1,1,0) are WB (which requires 4 bits).

In one example of Alt 4-4A, c_(0,0,0)=1, c_(1,1,0) ∈ {1,j, −1, −j},c_(1,0,0)=a_(1,0,0)b_(1,0,0) and c_(0,1,0)=a_(0,1,0)b_(0,1,0) wherea_(1,1,0) a_(0,1,0)

${\in {\left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\} \mspace{14mu} {and}\mspace{14mu} b_{1,0,0}}},{b_{0,1,0} \in \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}},$

where the calculation and reporting of c_(1,1,0), b_(1,0,0) andb_(0,1,0) can be SB (which requires 4 bits/SB), and the calculation andreport of a_(1,0,0) and a_(0,1,0) are WB (which requires 4 bits).

In one example of Alt 4-5A, the codebook are

$\left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\} \mspace{14mu} {and}\mspace{14mu} \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

are respectively replaced with any one of the following: a_(WB)={1,j,−1, −j} (2 bit WB phase) and a_(SB)={1, j} (1-bit SB phase);a_(WB)={1,j,−1, −j} (2 bit WB phase) and a_(SB)={1, −j} (1-bit SBphase); a_(WB)={1, j, −1, −j} (2 bit WB phase) and

$a_{SB} = \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

(1-bit SB phase);

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\}$

(2 bit WB phase) and

$a_{SB} = \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

(1-bit SB phase);

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\}$

(2 bit WB phase) and a_(SB)={1, −j} (1-bit SB phase); and

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\}$

(2 bit WB phase) and a_(SB)={1,j} (1-bit SB phase).

In one example of Alt 4-6A, c_(0,0,0)=1, c_(0,1,0) ∈ {1, j, −1, −j},c_(1,0,0) ∈ {1, j, −1, −j} and c_(1,1,0)=c_(0,1,0)×c_(1,0,0), where thecalculation and reporting of c_(1,0,0) is WB (which requires 2 bits),and that of c_(0,1,0) can be WB or SB (which requires 2 bits/SB).

At least one of the following embodiments may be used to support atleast one of the above alternatives. In one embodiment, only one of thealternatives is fixed in the specification (e.g. Alt 4-2A). In anotherembodiment, two of these alternatives are supported in the specification(e.g. Alt 4-6A, Alt 4-2A) and one of the two is configured to the UE(RRC). In another embodiment, one of the alternatives is eitherconfigured (via higher layer RRC signaling or dynamic DCI signaling) orUE reports a preferred alternative. In yet another embodiment, Alt 4-6Ais supported for both M=2 and 4, and Alt 4-2A is supported for M=2 only.Only one of these embodiments is specified in the specification.

For rank 2, the reporting of c_(0,1,l), c_(1,1,l), and c_(1,0,l) areaccording to at least one of the following alternatives. In one exampleof Alt 4-0B, c_(p,0,0)=c_(p,0,1), c_(p,1,0)=c_(p,1,1), c_(0,0,0)=1,c_(0,1,0) −{1, j}, c_(1,0,0) −{1, j, −1, −j}, c_(1,1,0)={1, j, −1, −j},where the calculation and reporting of c_(0,1,0), c_(1,0,0) andc_(1,1,0) can be SB (which requires 5 bits/SB).

In one example of Alt 4-1B, c_(p,0,0)=c_(p,0,1), c_(p,1,0)=−c_(p,1,1),c_(0,0,0)=1, c_(0,1,0) ∈ {1, j}, c_(1,0,0) ∈ {1, j,−1, −j},C_(1,1,0)=c_(0,1,0)·c_(1,0,0), where the calculation and reporting ofc_(0,1,0) and c_(1,0,0) can be SB (which requires 3 bits/SB).

In one example of Alt 4-2B, c_(p,0,0)=c_(p,0,1), c_(p,1,0)=c_(p,1,1),c_(0,0,0)=1, c_(0,1,0) ∈ {1,j}, c_(1,0,0)=a_(1,0,0)b_(1,0,0), andc_(1,1,0)=a_(1,1,0)b_(1,1,0) where

${{a_{1,r,0} \in {\left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\} \mspace{14mu} {and}\mspace{14mu} b_{1,r,0}}} = \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}},$

where the calculation and reporting of c_(0,1,0), b_(1,0,0) andb_(1,1,0) can be SB (which requires 3 bits/SB) and the calculation andreport of a_(1,0,0) and a_(1,1,0) are wideband (which requires 4 bits).

In one example of Alt 4-3B, c_(p,0,0)=c_(p,0,1), c_(p,1,0)=−c_(p,1,1),c_(0,0,0)=1, c_(1,0,0) ∈ {1,j}, c_(0,1,0)=a_(0,1,0)b_(0,1,0) andc_(1,1,0)=a_(1,1,0)b_(1,1,0) where

${a_{p,1,0} \in {\left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\} \mspace{14mu} {and}\mspace{14mu} b_{p,1,0}} \in \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}},$

where the calculation and reporting of c_(1,0,0), b_(0,1,0) andb_(1,1,0) can be SB (which requires 3 bits/SB), and the calculation andreport of a_(0,1,0) and a_(1,1,0) are WB (which requires 4 bits).

In one example of Alt 4-4B, c_(p,0,0)=c_(p,0,1), c_(p,1,0)=−c_(p,1,1),c_(0,0,0)=1, c_(1,1,0) ∈ {1,j}, c_(1,0,0)=a_(1,0,0)b_(1,0,0) andc_(0,1,0)=a_(0,1,0)b_(0,1,0) where a_(1,0,0),

${a_{0,1,0} \in {\left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\} \mspace{14mu} {and}\mspace{14mu} b_{1,0,0}}},{b_{0,1,0} \in \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}},$

where the calculation and reporting of c_(1,1,0), b_(1,0,0) andb_(0,1,0) can be SB (which requires 3 bits/SB), and the calculation andreport of a_(1,0,0) and a_(0,1,0) are WB (which requires 4 bits).

In one example of Alt 4-5B, the codebook are

$\left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\} \mspace{14mu} {and}\mspace{14mu} \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

are respectively replaced with any one of the following: a_(WB)={1,j,−1,−j} (2 bit WB phase) and a_(SB)={1,j} (1-bit SB phase); a_(WB)={1,j,−1,−j} (2 bit WB phase) and a_(SB)={1, −j} (1-bit SB phase); a_(WB)={1,j,−1, −j} (2 bit WB phase) and

$a_{SB} = \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

(1-bit SB phase);

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\; \pi}{4}},e^{\frac{j\; 7\; \pi}{4}}} \right\}$

(2 bit WB phase) and

$a_{SB} = \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

(1-bit SB phase);

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

(2 bit WB phase) and a_(SB)={1, −j} (1-bit SB phase); and

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

(2 bit WB phase) and a_(SB)={1,j} (1-bit SB phase).

In one example of Alt 4-6B, c_(p,0,0)=c_(p,0,1), c_(p,1,0)=−c_(p,1,1),c_(0,0,0)=1, c_(0,1,0) ∈ {1, j}, c_(1,0,0) ∈ {1, j, −1, −j},c_(1,1,0)=c_(0,1,0)·c_(1,0,0), where +the calculation and reporting ofc_(1,0,0) is WB (which requires 2 bits), and that of c_(0,1,0) can be WBor SB (which requires 1 bits/SB).

At least one of the following embodiments may be used to support atleast one of the above alternatives. In one embodiment, only one of thealternatives is fixed in the specification (e.g. Alt 4-2B). In anotherembodiment, two of these alternatives are supported in the specification(e.g. Alt 4-6B, Alt 4-2B) and one of the two is configured to the UE(RRC). In another embodiment, one of the alternatives is eitherconfigured (via higher layer RRC signaling or dynamic DCI signaling) orUE reports a preferred alternative. In yet another embodiment, Alt 4-6Bis supported for both M=2 and 4, and Alt 4-2B is supported for M=2 only.Only one of these methods is specified in the specification.

An alternative expression for

$a_{WB} = {{\left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\} \mspace{14mu} {and}\mspace{14mu} a_{SB}} = \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}}$

are as follows:

$a_{WB} = {\left\{ {{{e^{j\; {\pi {({\frac{k}{2} + \frac{1}{4}})}}}\text{:}\mspace{14mu} k} = 0},1,2,3} \right\} \mspace{14mu} {or}\mspace{14mu} \left\{ {{{e^{j\; {\pi {(\frac{{2k} + 1}{4})}}}\text{:}\mspace{14mu} k} = 0},1,2,3} \right\} \mspace{14mu} {or}}$$\left\{ {{{e^{\frac{j\; \pi}{4}}e^{\frac{j\; \pi \; k}{2}}\text{:}\mspace{14mu} k} = 0},1,2,3} \right\};{{{and}\mspace{14mu} a_{SB}} = {\left\{ {{{e^{j\; {\pi {({\frac{k}{2} - \frac{1}{4}})}}}:\mspace{14mu} k} = 0},1} \right\} \mspace{14mu} {or}}}$${\left\{ {{{e^{j\; {\pi {(\frac{{2k} - 1}{4})}}}\text{:}\mspace{14mu} k} = 0},1} \right\} \mspace{14mu} {or}\mspace{14mu} a_{SB}} = {\left\{ {{{e^{- \frac{j\; \pi}{4}}e^{\frac{j\; \pi \; k}{2}}\text{:}\mspace{14mu} k} = 0},1} \right\}.}$

In one embodiment 4A, the PMI codebook for rank 3 and 4 CSI reportingcomprises of the following pre-coding matrices

$W = {{\frac{1}{\sqrt{3\; {MP}}}\begin{bmatrix}w_{0,0,0} & w_{0,0,1} & w_{0,0,2} \\w_{0,1,0} & w_{0,1,1} & w_{0,1,2} \\w_{1,0,0} & w_{1,0,1} & w_{1,0,2} \\w_{1,1,0} & w_{1,1,1} & w_{1,1,2}\end{bmatrix}}\mspace{14mu} {and}}$${W = {\frac{1}{\sqrt{4\; {MP}}}\begin{bmatrix}w_{0,0,0} & w_{0,0,1} & w_{0,0,2} & w_{0,0,3} \\w_{0,1,0} & w_{0,1,1} & w_{0,1,2} & w_{0,1,3} \\w_{1,0,0} & w_{1,0,1} & w_{1,0,2} & w_{1,0,3} \\w_{1,1,0} & w_{1,1,1} & w_{1,1,2} & w_{1,1,3}\end{bmatrix}}},$

respectively, where:w_(p,r,l)=b_(k) ₁ _(+k′) _(1,l) _(,k) ₂ _(+k′)_(2,l) ·c_(p,r,l), p=0,1 (for two panels), r=0,1 (for twopolarizations), l=0,1,2,3 (for four layers); b_(k) ₁ _(+k′) _(1,l) _(,k)₂ _(+k′) _(2,l) is an oversampled 2D DFT beam; k₁=i_(1,1), k₂=i_(1,2)and the leading beam index (i_(1,1),i_(1,2)) is reported wideband, wherei_(1,1)=0, 1, . . . N₁O₁−1 and i_(1,2)=0,1, . . . N₂O₂−1, hence itrequires | log₂(N₁O₁N₂O₂)|1 bits; for layer 0 and 1 (1=0, 1), the indexpair (k′_(1,l), k′_(2.1))=(0,0); for layer 2 and 3 (l=2, 3), the indexpair (k′_(1,l), k′_(2,l)) is calculated and reported in a widebandmanner according to at least one of the following alternatives.

One of the alternatives is supported in the specification. In oneexample of Alt 4A-0, the same as in LTE Release 13/14 Class A rank 3-4codebook for Codebook-Config=1, i.e., (k′_(1,1), k′_(2,1)) ∈ {(1,0),(0,1)} for 2D antenna port layouts (N₁>1, N₂>1), and (k′_(1,1),k′_(2,1)) ∈ {(1,0), (2,0), (3,0)} for 1D antenna port layouts (N₁>1,N₂=1).

In one example of Alt 4A-1, (k′_(1,1), k′_(2,1)) ∈ {(1,0), (0,1)} for 2Dantenna port layouts (N₁>1, N₂>1), and (k′_(1,1),k′_(2,1)) ∈ {(1,0),(2,0)} for 1D antenna port layouts (N₁>1, N₂=1).

In one example of Alt 4A-2, for N₁>1 and N₂>2 andN₂>N_(1:)(k′_(1,1),k′_(2,1))={(0,0), (O₁, 0), (0, O₂), (0, 2O₂)}; forN₂>1 and N₁>2 and N₂>N₁: (k′_(1,1),k′_(2,1))={(0,0), (O₁, 0), (0, O₂),(2O₁, 0)}; for N₂>1 and N₁>1 and N₁=N₂: (k′_(1,1), k′_(2,1))={(0,0),(O₁, 0), (0, O₂), (O₁, O₂)}; and for N₂=1: (k′_(1,1), k′_(2,1))={(0,0),(O₁, 0), (2O₁, 0), (3O₁, 0)} The last two values are not applicable for4 ports (i.e., N₁=2).

In one example of Alt 4A-3, for N₁>1 and N₂ >2 and N₂>N₁:(k′_(1,1),K′_(2,1) 0={(0,0), (O₁, 0), (0, O₂), (0, (N₂−1)O₂)}; for N₂>1and N₁>2 and N₁>N₂: (k′_(1,1),k′_(2,1))={(0,0), (O₁, 0), (0, O₂),((N₁−1)O₁, 0)}; for N₂>1 and N₁>1 and N₁=N₂: (k′_(1,1),K′_(2.1))={(0,0),(O₁, 0), (0, O₂), (O_(1,) O₂)}; and for N₂=1:(k′_(1,1),k′_(2,1))={(0,0), (O₁, 0), (2O₁, 0), ((N₁−1)O₁, 0)}. The lasttwo values are not applicable for 4 ports (i.e., N₁=2).

In one example of Alt 4A-4, for N₂>1 and N₁ >1:(k′_(1,1),k′_(2,1))={(0,0), (O₁, 0), (0,O₂), (O₁,O₂)}; and for N₂=1:(k′_(1,1), k′_(2,1))={(0,0), (O₁, 0), (2O₁,0), (3O₁,0)}. The last twovalues are not applicable for 4 ports (i.e., N₁=2).

In one example of Alt 4A-5, for N₂>1 and N₁>1: (k′_(1,1),k′_(2,1))={(0,0), (O₁, 0), (0, O₂), (O₁, O₂)}; and for N₂=1: (k′_(1,1),k′_(2,1))={(0,0), (O₁, 0), (2O₁, 0), ((N₁−1)O₁,0)}. The last two valuesare not applicable for 4 ports (i.e., N₁=2).

c_(p,r,l) is the co-phase value for panel p, polarization r and layer l.The reporting of c_(p,r,l) is according to the codebook in at least oneof Alt 4-0A through Alt 4-5A or/and Alt 4-0B through Alt 4-5B.

In one embodiment 4B, the PMI codebook for rank 5, rank 6, rank 7, and 8CSI reporting comprises of the following pre-coding matrices

$\mspace{20mu} {{W = {\frac{1}{\sqrt{5\; {MP}}}\begin{bmatrix}w_{0,0,0} & w_{0,0,1} & w_{0,0,2} & w_{0,0,3} & w_{0,0,4} \\w_{0,1,0} & w_{0,1,1} & w_{0,1,2} & w_{0,1,3} & w_{0,1,4} \\w_{1,0,0} & w_{1,0,1} & w_{1,0,2} & w_{1,0,3} & w_{1,0,4} \\w_{1,1,0} & w_{1,1,1} & w_{1,1,2} & w_{1,1,3} & w_{1,1,4}\end{bmatrix}}},\mspace{20mu} {W = {\frac{1}{\sqrt{6\; {MP}}}\begin{bmatrix}w_{0,0,0} & w_{0,0,1} & w_{0,0,2} & w_{0,0,3} & w_{0,0,4} & w_{0,0,5} \\w_{0,1,0} & w_{0,1,1} & w_{0,1,2} & w_{0,1,3} & w_{0,1,4} & w_{0,1,5} \\w_{1,0,0} & w_{1,0,1} & w_{1,0,2} & w_{1,0,3} & w_{1,0,4} & w_{1,0,5} \\w_{1,1,0} & w_{1,1,1} & w_{1,1,2} & w_{1,1,3} & w_{1,1,4} & w_{1,1,5}\end{bmatrix}}},{W = {\frac{1}{\sqrt{7\; {MP}}}\begin{bmatrix}w_{0,0,0} & w_{0,0,1} & w_{0,0,2} & w_{0,0,3} & w_{0,0,4} & w_{0,0,5} & w_{0,0,6} \\w_{0,1,0} & w_{0,1,1} & w_{0,1,2} & w_{0,1,3} & w_{0,1,4} & w_{0,1,5} & w_{0,1,6} \\w_{1,0,0} & w_{1,0,1} & w_{1,0,2} & w_{1,0,3} & w_{1,0,4} & w_{1,0,5} & w_{1,0,6} \\w_{1,1,0} & w_{1,1,1} & w_{1,1,2} & w_{1,1,3} & w_{1,1,4} & w_{1,1,5} & w_{1,1,6}\end{bmatrix}}},{W = {\frac{1}{\sqrt{8\; {MP}}}\begin{bmatrix}w_{0,0,0} & w_{0,0,1} & w_{0,0,2} & w_{0,0,3} & w_{0,0,4} & w_{0,0,5} & w_{0,0,6} & w_{0,0,7} \\w_{0,1,0} & w_{0,1,1} & w_{0,1,2} & w_{0,1,3} & w_{0,1,4} & w_{0,1,5} & w_{0,1,6} & w_{0,1,7} \\w_{1,0,0} & w_{1,0,1} & w_{1,0,2} & w_{1,0,3} & w_{1,0,4} & w_{1,0,5} & w_{1,0,6} & w_{1,0,7} \\w_{1,1,0} & w_{1,1,1} & w_{1,1,2} & w_{1,1,3} & w_{1,1,4} & w_{1,1,5} & w_{1,1,6} & w_{1,1,7}\end{bmatrix}}}}$

respectively.

In such embodiment, w_(p,r,l)=b_(k) ₁ _(+k′) _(1,l) _(,k) ₂ _(+k′)_(2,l) ·c_(p,r,l), p=0,1 (for two panels), r=0,1 (for twopolarizations), l=0,1,2,3,5,6,7,8 (for up to eight layers), b_(k) ₁_(+k′) _(1,i) _(,k) ₂ _(+k′) _(2,i) is an oversampled 2D DFT beam,k₁=i_(1,1),k₂=i_(1,2) and the leading beam index (i_(1,1),i_(1,2)) isreported wideband, where i_(1,1)=0, 1, . . . N₁O₁−1 and i_(1,2)=0,1, . .. N₂O₂−1, hence it requires |log₂(N₁O₁N₂O₂)|bits.

For layer 0 and 1 (l=0, 1), the index pair(k′_(1,l),k′_(2,l))=(b_(1,0),b_(2,0)), for layer 2 and 3 (l=2, 3), theindex pair (k′_(1,l),k′_(2,1))=(b_(1,1), b_(2,1)), for layer 4 and 5(l=4, 5), the index pair (k′_(1,l),k′_(2.1))=(b_(1,2), b_(2,2)), and forlayer 6 and 7 (1=6, 7), the index pair(k′_(1,l),k′_(2,1))=(b_(1,2),b_(2,3)), where (b_(1,0),b_(2,0)),(b_(1,1),b_(2,1)), (b_(1,2),b_(2,2)), and (b_(1,3),b_(2,3)) fordifferent layers are determined according to at least one of thefollowing alternatives.

In one example of Alt 4B-0, (b_(1,0), b_(2,0)), (b_(1,1), b_(2,1)),(b_(1,2), b_(2,2)), and (b_(1,3), b_(2,3)) are determined based on fixedorthogonal beam patterns (similar to Rel. 13/14 LTE Class A rank 5-8)using higher layer RRC parameter Codebook-Config, whereCodebook-Config=1,2,3,4 which correspond to the orthogonal beam groupsin LTE specification Class A rank 5-8.

In one example of Alt 4B-1, Alt 4B-0 in which UE reports a preferredorthogonal beam group using a 2-bit CSI reporting which is reported in aWB manner. This reporting can be separate or joint with other WB CSIreports such as (PMI i₁). Alternatively, the reporting can be restrictedto 1 bit.

In one example of Alt 4B-2, (b_(1,0), b_(2,0)), (b_(1,1),b_(2,1)),(b_(1,2), b_(2,2)), and (b_(1,3), b_(2,3)) are determined based onindependent or free selection from full orthogonal DFT basis comprisingof N₁N₂ orthogonal beams.

The extension of embodiment 4 to M>2 antenna panels, for example M=4, isstraightforward to those the skilled in the art.

In one embodiment 5, the UE is configured with the CQI reporting, inaddition to RI/PMI, according to at least one of the followingalternatives. In one example of Alt 5-0, a joint CQI common for allpanels is reported. An example use case of this alternative is when alllayers are transmitted from all panels. In one example of Alt 5-1, perpanel CQI is reported, i.e. M CQIs are reported in total. An example usecase of this alternative is when different layers are transmitted fromdifferent panels. For example, layer 0 is transmitted from panel 0,layer 1 is transmitted from panel 1, and so on.

In one embodiment 6, the UE is configured with the RI reporting, inaddition to CQI/PMI, according to at least one of the followingalternatives. In one example of Alt 6-0, RI =M is fixed, and hence no RIis reported. In one example of Alt 6-1, a joint RI common for all panelsis reported. An example use case of this alternative is when all layersare transmitted from all panels. In one example of Alt 5-2, per panel RIis reported, i.e. M RIs are reported in total. An example use case ofthis alternative is when different layers are transmitted from differentpanels. For example, at least one of layer 0 and 1 is transmitted frompanel 0, at least one of layer 2 and 3 is transmitted from panel 1, andso on. In this case, each reported RI can be 1 bit.

In one embodiment 7, the UE is configured with the CRI reporting eitheralone or together with CSI reports CQI/PMI/RI.

In one embodiment 8, the UE is configured the CSI reporting for hybridbeamforming architecture comprising of both radio frequency (RF) oranalog beams (precoding) in addition to the digital or basebandprecoding. In addition, the beams in the W1 codebook is used to reportanalog beam and W2 is used to report inter-panel or/and intra-panelphase where the W₂ codebook is according to some embodiment of thepresent disclosure.

In one embodiment 9, the UE is configured with the SB sizes K₁ and K₂respectively for inter-panel co-phasing and intra-panel(inter-polarization) co-phasing. A few alternatives for (K₁, K₂) are asfollows. In one example of Alt 9-0, K₁=K₂ In one example of Alt 9-1,K₁=r×K₂, where r is an integer, for example belonging to {1, 2, 3, 4}.In one example of Alt 9-2, K₂=r×K₁, where r is an integer, for examplebelonging to {1, 2, 3, 4}. In one example of Alt 9-3, K₁=r×K₂, where ris an integer or 1 or a fraction, for example belonging to {¼, ⅓, ½, 1,2, 3, 4}. In one example of Alt 9-4, Alt -3 where the r value depends onthe system bandwidth (BW). For example, for smaller BWs, r=1, and forlarger BWs, r=2 or 4. In one example of Alt 9-5, a single (K₁, K₂)according to one of Alt 9-0 to Alt 9-3 is configured either higher layerRRC or dynamic MAC CE based or DCI signaling. In one example of Alt 9-6,the K₁ value is configured via higher layer RRC or dynamic MAC CE basedor DCI signaling and the K₂ value is fixed, either BW-dependent orBW-independent. In one example of Alt 9-7, the K₂ value is configuredvia higher layer RRC or dynamic MAC CE based or DCI signaling and the K₁value is fixed, either BW-dependent or BW-independent. In one example ofAlt 9-8, a combination of at least one of Alt 9-0 through Alt 9-7.

In one embodiment, only one of the alternatives is fixed in thespecification. In another embodiment, one of the alternatives is eitherconfigured (via higher layer RRC signaling or dynamic DCI signaling) orUE reports a preferred alternative

In one embodiment 10, for M=4, a UE is configured with a PMI codebookfor CSI feedback according to at least one of the followingalternatives. In one example of Alt 10-0 (panel selection), 2 out of 4panels are selected, and then the PMI codebook for 2 panels is used toreport PMI for the selected two panels. This panel selection can bereported either in a WB manner or per SB, where this reporting requires

$\left\lceil {\log_{2}\begin{pmatrix}4 \\2\end{pmatrix}} \right\rceil = 3$

bits which can be reported either jointly with other WB/SB CSIcomponents such as PMI1/PMI2 or separately as a separate WB/SB CSIreport. In an example, panel selection is reported using CRI (CSI-RSresource indicator).

In one example of Alt 10-1 (panel/polarization combination selection), 4out of 8 panel and polarization combinations (2 polarizations and 4panels, hence 8 combinations) are selected, and then the PMI codebookfor 2 panels (which is equivalent to 4 panel and polarizationcombinations) is used to report PMI for the selected four panel andpolarization combinations. This panel/polarization combination selectioncan be reported either in a WB manner or per SB, where this reportingrequires

$\left\lceil {\log_{2}\begin{pmatrix}8 \\4\end{pmatrix}} \right\rceil = 7$

bits which can be reported either jointly with other WB/SB CSIcomponents such as PMI1/PMI2 or separately as a separate WB/SB CSIreport. In an example, panel/polarization combination selection isreported using CRI (CSI-RS resource indicator)

In one example of Alt 10-2, for rank 1 W₂=[c_(0,0,0) c_(0,1,0) c_(1,0,0)c_(1,1,0) c_(2,0,0) c_(2,1,0) c_(3,0,0) c_(3,1,0)]^(T). In such example,p=0: c_(0,0,0)=1, c_(1,1,0) ∈ {1, j, −1, −j} is reported SB (requires 2bits for reporting), and p>0, r=0,1,: c_(p,r,0)=a_(p,r,0)b_(p,r,0) where

$a_{p,r,0} \in \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

is reported WB and

$b_{p,r,0} \in \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

is reported SB (hence, requires 12 WB bits and 6 SB bit). In total, thisalternative requires, 12 WB bits to report WB part of the phase and 8 SBbits to report SB part of the phase. For rank 2, c_(p,0,1)=c_(p,0,0) andc_(p,1,1)=−c_(p,1,0).

In one example of Alt 10-3, for rank 1 W₂=[c_(0,0,0) c_(0,1,0) c1,0,0c1,1,0 c_(2,0,0) c2,1,0 c_(3,0,0) c_(3,1,0]) ^(T), p=0,1,2,3, and r=0,1: c_(p,r,0)=a_(p,r,0)b_(p,r,0) where

$a_{p,r,0} \in \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

is reported WB and

$b_{p,r,0} \in \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

is reported SB. In total, this alternative requires, 14 WB bits toreport WB part of the phase and 7 SB bits to report SB part of thephase. For rank 2, c_(p,0,1)=c_(p,0,0) and c_(p,1,1)=c_(p,1,0).

In one example of Alt 10-4, for rank 1 W₂=[c_(0,0,0) c_(0,1,0) c_(1,0,0)c_(1,1,0) c_(2,0,0) c_(2,1,0) c_(3,0,0) c_(3,1,0)]^(T), p=0:c_(0,0,0)=1, c_(1,1,0) ∈ {1, j, −1, −j} is reported SB (requires 2 bitsfor reporting), and p>0, r=0,1,: c_(p,0,0)=c_(p,1,0)=a_(p,r,0)b_(p,r,0)where

$a_{p,r,0} \in \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\; \pi}{4}},e^{\frac{j\; 5\pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

is reported WB and

$b_{p,r,0} \in \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

is reported SB (hence, requires 6 WB bits and 3 SB bit). In total, thisalternative requires, 6 WB bits to report WB part of the phase and 5 SBbits to report SB part of the phase. For rank 2, c_(p,0,1)=c_(p,0,0) andc_(p,1,1)=−c_(p,1,0).

In one example of Alt 10-5, for rank 1 W₂=[c_(0,0,0) c_(0,1,0) c_(1,0,0)c_(1,1,0) c_(2,0,0) c_(2,1,0) c_(3,0,0) c_(3,1,0)]^(T),p=0, 1, 2, 3, andr=0, 1: c_(p,0,0)=c_(p,1,0)=a_(p,r,0)b_(p,r,0) where

$a_{p,r,0} \in \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\pi}{4}},e^{\frac{j\; 5\pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

is reported WB and

$b_{p,r,0} \in \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

is reported SB. In total, this alternative requires, 8 WB bits to reportWB part of the phase and 4 SB bits to report SB part of the phase. Forrank 2, c_(p,0,1)=c_(p,0,0) and c_(p,1,1)=−c_(p,1,0).

In one embodiment 11, a UE is configured with a PMI codebook for multipanels (N_(g)=M>1) for all ranks (e.g. 1-8), which can be constructedfrom the single panel PMI codebook (N_(g)=M=1) by the followingpre-coder relation: w_(p,r,l)=b_(k) ₁ _(+k′) _(1,l) _(,k) ₂ _(+k′)_(2,1) ·c_(p,r,l), where p=0,1, . . . , N_(g)−1 (panel, where N₉ denotesthe number of panels), r=0,1 (two polarizations), l=0,1, . . . , R−1(layers, where R denotes rank), b_(k) ₁ _(+k′) _(1,l) _(,k′) _(2,l)corresponds to a single 2D DFT beam (L=1) in the W₁ codebook; where(k′_(1,l),k′_(2,l))=(0,0) for rank 1 and 2, is according to Embodiment4A and 4B for rank 3-8, and c_(p,r,l) is co-phasing coefficient betweenpanels and polarizations. The inter-panel co-phasing payload isconfigurable via RRC. In one example of Mode 1, this mode corresponds tolower payload, and is supported for both N_(g)=2 or 4. In one example ofMode 2, his mode corresponds to higher payload, and at least supportedfor N_(g)=2. For N_(g)=4, this mode can be supported with maximum 4bits/subband according to at least one alternative in the aforementionedembodiment 10.

For rank 1, c_(p,r,0) is given as follows. In one example of Mode 1,c_(0,0,0)=1, c_(0,1,0) ∈ {1, j, −1, −j}, c_(p,0,0) ∈ {1, j, −1, −j} andc_(p,1,0)=c_(0,1,0)×c_(p,0,0). In such mode, the calculation andreporting of c_(0,1,0) can be subband (requires 2 bits/subband). In suchmode, the calculation and reporting of c_(p,0,0) is wideband (requires2×(N_(g)−1) bits).

In one example of Mode 2, c_(0,0,0)=1,c_(0,1,0) ∈ {1,j,−1,−j}andc_(p,r,0) =a_(p,r,0)×b_(p,r,0) where p>0,

$a_{p,r,0} \in {\left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\pi}{4}},e^{\frac{j\; 5\pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\} \mspace{14mu} {and}\mspace{14mu} b_{p,r,0}} \in {\left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}.}$

In such mode, the calculation and reporting of c_(0,1,0) and b_(p,r,0)can be subband (2+2×(N_(g)1) bits/subband). In such mode, thecalculation and reporting of a_(p,r,0) is wideband (4×(N_(g)−1) bits).

For rank 2,

$c_{p,r,l} = {\frac{c_{r,l}}{c_{r,0}} \times c_{p,r,0}}$

for l=1, c_(0,1,0) ∈ {1, j}, c_(p,0,1)=c_(p,0,0) andc_(p,1,1)=−c_(p,1,0)·c_(0,0)=c_(0,1)=1,c_(1,0)=−c_(1,1), and c_(1,0) ∈{1, j} and c_(p,r,0) is given in the above rank 1 MP codebook for eachmode. For ranks 3-8, the codebook in (or their extension) theaforementioned embodiments 4A and 4B can be used.

In one embodiment 12, a UE is configured with a PMI codebook for multipanels (N_(g)=M>1) as follows. For 8 antenna ports (e.g. {15, 16, . . ., 22}), 16 antenna ports (e.g. {15, 16, . . . , 30}), 32 antenna ports(e.g. {15, 16, . . . , 46}), when the number of layers v=1, each PMIvalue corresponds to four codebook indices i_(1,1), i_(1,2), i_(1,4), i₂and when the number of layers v∈ {2,3,4}, each PMI value corresponds tofive codebook indices i_(1,1), i_(1,2), i_(1,3), i_(1,4), i₂. Thecodebooks for 1-4 layers are given respectively in TABLES 8-11. Themapping from i_(1,3) to k₁ and k₂ for 2-layer reporting is given inTABLE 6. The mapping from i_(1,3) to k₁ and k₂ for 3-layer and 4-layerreporting is given in TABLE 7. The quantities φ_(n), a_(p), b_(p),u_(m), and v_(lm) are given by:

ϕ_(n) = e^(j π n/2)a_(p) = e^(j π(p/2 + 1/4)) = e^(j π/4)e^(j π p/2)b_(p) = e^(j π(p/2 − 1/4)) = e^(−j π/4)e^(j π p/2)$u_{m} = \left\{ {{\begin{matrix}\begin{bmatrix}1 & e^{j\frac{2\pi \; m}{O_{2}N_{2}}} & \ldots & e^{j\frac{2\pi \; {m{({N_{2} - 1})}}}{O_{2}N_{2}}}\end{bmatrix} & {N_{2} > 1} \\1 & {N_{2} = 1}\end{matrix}v_{l,m}} = {\begin{bmatrix}u_{m} & {e^{j\frac{2\pi \; l}{O_{1}N_{1}}}u_{m}} & \ldots & {e^{j\frac{2\pi \; {l{({N_{1} - 1})}}}{O_{1}N_{1}}}u_{m}}\end{bmatrix}^{T}.}} \right.$

The values of N_(g), N₁, and N₂ are configured with the higher-layerparameters CodebookConfig-Ng, CodebookConfig-N1 and CodebookConfig-N2,respectively. The supported configurations of (N_(g),N₁,N₂) for a givennumber of CSI-RS ports and the corresponding values of (O₁,O₂) are givenin TABLE 4. The number of CSI-RS ports, P_(CSI-RS), is 2N_(g)N₁N₂.

A UE may only use i_(1,2)=0 and may not report i_(1,2) if the value ofCodebookConfig-N2 is set to 1.

TABLE 6 Mapping of i_(1, 3) to k₁ and k₂ for 2-layer CSI reporting forN_(g) ∈ {2, 4} N₁ = 4, N₂ = 2 N₁ = 2, N₂ = 2 N₁ = 2, N₂ = 1 N₁ > 2, N₂ =1 i_(1,3) k₁ k₂ k₁ k₂ k₁ k₂ k₁ k₂ 0 0 0 0 0 0 0 0 0 1  O₁ 0 O₁ 0 O₁ 0 O₁ 0 2 0 O₂ 0 O₂ 2O₁ 0 3 2O₁ 0 O₁ O₂ 3O₁ 0

TABLE 7 Mapping of i_(1, 3) to k₁ and k₂ for 3-layer and 4-layer CSIreporting for N_(g) ∈ {2, 4} N₁ = 2, N₂ = 1 N₁ = 4, N₂ = 1 N₁ = 8, N₂ =1 N₁ = 2, N₂ = 2 N₁ = 4, N₂ = 2 i_(1, 3) k₁ k₂ k₁ k₂ k₁ k₂ k₁ k₂ k₁ k₂ 0O₁ 0  O₁ 0  O₁ 0 O₁ 0 O₁ 0 1 2O₁ 0 2O₁ 0 0 O₂ 0 O₂ 2 3O₁ 0 3O₁ 0 O₁ O₂O₁ O₂ 3 4O₁ 0 2O₁  0

TABLE 8 Codebook for 1-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) ∈ {2, 4} i_(1,1) i_(1,2)i_(1,4) i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . ,4^(N) ^(g) ⁻¹ − 1 0, 1, 2, 3 W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4)_(,i) ₂ ⁽¹⁾ $\quad\begin{matrix}{{{{for}\mspace{14mu} N_{g}} = 2},{{W_{l,m,p,n}^{(1)} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p}v_{l,m}} \\{\phi_{p}\phi_{n}x_{l,m}}\end{bmatrix}}};{and}}} \\{{{{for}\mspace{14mu} N_{g}} = 4},{{W_{l,m,p,n}^{(1)} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}}\end{bmatrix}}};{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = {p.}}}}\end{matrix}$ Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4) i₂0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 15 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,i) ₂ ⁽¹⁾$\quad\begin{matrix}{{{{where}\mspace{14mu} W_{l,m,p,n}^{(1)}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}}\end{bmatrix}}};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p};} \\{{n_{1} = \left\lfloor \frac{n}{4} \right\rfloor};{n_{2} = {\left\lfloor \frac{n}{2} \right\rfloor \mspace{11mu} {mod}\; 2}};{n_{3} = {n\mspace{14mu} {mod}\; 2}};}\end{matrix}$

TABLE 9 Codebook for 2-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) ∈ {2, 4} i_(1,1) i_(1,2)i_(1,4) i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . ,4^(N) ^(g) ⁻¹ − 1 0, 1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2)_(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽²⁾ $\quad\begin{matrix}{{{{for}\mspace{14mu} N_{g}} = 2},{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} \\{\phi_{p}\phi_{n}v_{l,m}} & {{- \phi_{p}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};{and}}} \\{{{{for}\mspace{14mu} N_{g}} = 4},{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {{- \phi_{p_{1}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {{- \phi_{p_{2}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}} & {{- \phi_{p_{3}}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = {p.}}}}\end{matrix}$ Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4) i₂0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 15 0, . . . , 7W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,i) ₂ ⁽²⁾ $\quad\begin{matrix}{{{{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {\frac{1}{\sqrt{2\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {{- \phi_{n_{1}}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p};} \\{{n_{1} = \left\lfloor \frac{n}{4} \right\rfloor};{n_{2} = {\left\lfloor \frac{n}{2} \right\rfloor \mspace{11mu} {mod}\; 2}};{n_{3} = {n\mspace{14mu} {mod}\; 2}};}\end{matrix}$

TABLE 10 Codebook for 3-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) ∈ {2, 4} i_(1,1) i_(1,2)i_(1,4) i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . ,4^(N) ^(g) ⁻¹ − 1 0, 1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2)_(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽³⁾ $\quad\begin{matrix}{{{{for}\mspace{14mu} N_{g}} = 2},{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} \\{\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} & {\phi_{p}v_{l,m}} \\{\phi_{p}\phi_{n}v_{l,m}} & {\phi_{p}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p}}\phi_{n}v_{l,m}}\end{bmatrix}}};{and}}} \\{{{{for}\mspace{14mu} N_{g}} = 4},{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {\phi_{p_{1}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{1}}}\phi_{n}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {\phi_{p_{2}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{2}}}\phi_{n}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{3}}v_{l,m}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}} & {\phi_{p_{3}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{3}}}\phi_{n}v_{l,m}}\end{bmatrix}}};{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = {p.}}}}\end{matrix}$ Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4) i₂0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 15 0, . . . , 7W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,i) ₂ ⁽³⁾ $\quad\begin{matrix}{{{{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)}} = {\frac{1}{\sqrt{3P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n_{1}}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} & {a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{3}}}b_{n_{3}}v_{l,m}}\end{bmatrix}}};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p};} \\{{n_{1} = \left\lfloor \frac{n}{4} \right\rfloor};{n_{2} = {\left\lfloor \frac{n}{2} \right\rfloor \mspace{11mu} {mod}\; 2}};{n_{3} = {n\mspace{14mu} {mod}\; 2}};}\end{matrix}$

TABLE 11 Codebook for 4-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) ∈ {2, 4} i_(1,1) i_(1,2)i_(1,4) i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . ,4^(N) ^(g) ⁻¹ − 1 0, 1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2)_(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽⁴⁾ $\quad\begin{matrix}{{{{for}\mspace{14mu} N_{g}} = 2},{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} & {\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} \\{\phi_{p}\phi_{n}v_{l,m}} & {\phi_{p}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p}}\phi_{n}v_{l,m}} & {{- \phi_{p}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};{and}}} \\{{{{for}\mspace{14mu} N_{g}} = 4},{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {\phi_{p_{1}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{1}}}\phi_{n}v_{l,m}} & {{- \phi_{p_{1}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {\phi_{p_{2}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{2}}}\phi_{n}v_{l,m}} & {{- \phi_{p_{2}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}} & {\phi_{p_{3}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{3}}}\phi_{n}v_{l,m}} & {{- \phi_{p_{3}}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = {p.}}}}\end{matrix}$ Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4) i₂0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 4^(N) ^(g) ⁻¹ −1 0, 1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k)₂ _(,i) _(1,4) _(,i) ₂ ⁽⁴⁾ $\quad\begin{matrix}{{{{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)}} = {\frac{1}{\sqrt{4P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n_{1}}}v_{l,m}} & {{- \phi_{n_{1}}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} & {a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{3}}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p};} \\{{n_{1} = \left\lfloor \frac{n}{4} \right\rfloor};{n_{2} = {\left\lfloor \frac{n}{2} \right\rfloor \mspace{11mu} {mod}\; 2}};{n_{3} = {n\mspace{14mu} {mod}\; 2}};}\end{matrix}$

In one embodiment 12A, for Codebook-Config=1, two separate codebooktables are used for N_(g)=2 and N_(g)=4, as shown in TABLES 12-15 for1-layer, 2-layer, 3-layer, and 4-layer, respectively.

TABLE 12 Codebook for 1-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1, 2, 3 0, 1, 2, 3W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,i) ₂ ⁽¹⁾${{where}\mspace{14mu} W_{l,m,p,n}^{(1)}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p}v_{l,m}} \\{\phi_{p}\phi_{n}x_{l,m}}\end{bmatrix}}$ Codebook-Config = 1, N_(g) = 4 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 63 0, 1, 2,3 W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,i) ₂ ⁽¹⁾${{{w{here}}\mspace{14mu} W_{l,m,p,n}^{(1)}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{1}}\phi_{n}x_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{p_{3}}\phi_{n}x_{l,m}}\end{bmatrix}}};{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p}$

TABLE 13 Codebook for 2-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1, 2, 3 0, 1 W_(i)_(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i)_(1,4) _(,i) ₂ ⁽²⁾${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {\frac{1}{\sqrt{2\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} \\{\phi_{p}\phi_{n}v_{l,m}} & {{- \phi_{p}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}$ Codebook-Config = 1, N_(g) = 4 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 63 0, 1W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,i) ₂ ⁽²⁾${{{w{here}}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {\frac{1}{\sqrt{2\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {{- \phi_{p_{1}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {{- \phi_{p_{2}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}} & {{- \phi_{p_{3}}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p}$

TABLE 14 Codebook for 3-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1, 2, 3 0, 1 W_(i)_(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i)_(1,4) _(,i) ₂ ⁽³⁾${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)}} = {\frac{1}{\sqrt{3P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} \\{\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} & {\phi_{n}v_{l,m}} \\{\phi_{p}\phi_{n}v_{l,m}} & {\phi_{p}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p}}\phi_{n}v_{l,m}}\end{bmatrix}}$ Codebook-Config = 1, N_(g) = 4 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 63 0, 1W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,i) ₂ ⁽³⁾${{{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)}} = {\frac{1}{\sqrt{3\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {\phi_{p_{1}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{1}}}\phi_{n}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {\phi_{p_{2}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{2}}}\phi_{n}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{3}}v_{l,m}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}} & {\phi_{p_{3}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{3}}}\phi_{n}v_{l,m}}\end{bmatrix}}};{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p}$

TABLE 15 Codebook for 4-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1, 2, 3 0, 1 W_(i)_(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i)_(1,4) _(,i) ₂ ⁽⁴⁾${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)}} = {\frac{1}{\sqrt{4\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} & {\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} \\{\phi_{p}\phi_{n}v_{l,m}} & {\phi_{p}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p}}\phi_{n}v_{l,m}} & {{- \phi_{p}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}$ Codebook-Config = 1, N_(g) = 4 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 63 0, 1W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,i) ₂ ⁽⁴⁾${{{w{here}}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)}} = {\frac{1}{\sqrt{4\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {\phi_{p_{1}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{1}}}\phi_{n}v_{l,m}} & {{- \phi_{p_{1}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {\phi_{p_{2}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{2}}}\phi_{n}v_{l,m}} & {{- \phi_{p_{2}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}} & {\phi_{p_{3}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{3}}}\phi_{n}v_{l,m}} & {{- \phi_{p_{3}}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p}$

In one embodiment 12B, for Codebook-Config=1, and N_(g)=4, instead ofjoint reporting of p₁, p₂, and p₃ using i_(i,4), CSI is reportedseparately using indices (i_(1,4,1), i_(1,4,2), i_(1,4,3)) or (i_(1,4),i_(1,5), i_(1,6)) for (p₁, p₂, p₃). The codebook tables for 1-4 layersare shown in TABLES 16-19.

TABLE 16 Codebook for 1-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) = 4 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i_(1,4,3) i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . ,N₂O₂ − 1 0, 1, 2, 3 0, 1, 2, 3 0, 1, 2, 3 0, 1, 2, 3 W_(i) _(1,1) _(,i)_(1,2) _(,i) _(1,4,1) _(,i) _(1,4,2) _(,i) _(1,4,3) _(,i) ₂ ⁽¹⁾${{where}\mspace{14mu} W_{l,m,p_{1},p_{2},p_{3},n}^{(1)}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}}\end{bmatrix}}$

TABLE 17 Codebook for 2-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) = 4 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i_(1,4,3) i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . ,N₂O₂ − 1 0, 1, 2, 3 0, 1, 2, 3 0, 1, 2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1)_(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4,1) _(,i) _(1,4,2)_(,i) _(1,4,3) _(,i) ₂ ⁽²⁾${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p_{1},p_{2},p_{3},n}^{(2)}} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {{- \phi_{p_{1}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {{- \phi_{p_{2}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}} & {{- \phi_{p_{3}}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}$

TABLE 18 Codebook for 3-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) = 4 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i_(1,4,3) i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . ,N₂O₂ − 1 0, 1, 2, 3 0, 1, 2, 3 0, 1, 2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1)_(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4,1) _(,i) _(1,4,2)_(,i) _(1,4,3) _(,i) ₂ ⁽³⁾$\quad{{{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p_{1},p_{2},p_{3},n}^{(3)}} = {\frac{1}{\sqrt{3\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {\phi_{p_{1}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{1}}}\phi_{n}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {\phi_{p_{2}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{2}}}\phi_{n}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{3}}v_{l,m}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}} & {\phi_{p_{3}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{3}}}\phi_{n}v_{l,m}}\end{bmatrix}}}$

TABLE 19 Codebook for 4-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) = 4 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i_(1,4,3) i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . ,N₂O₂ − 1 0, 1, 2, 3 0, 1, 2, 3 0, 1, 2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1)_(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4,1) _(,i) _(1,4,2)_(,i) _(1,4,3) _(,i) ₂ ⁽⁴⁾$\quad{{{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p_{1},p_{2},p_{3},n}^{(4)}} = {\frac{1}{\sqrt{4\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {\phi_{p_{1}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{1}}}\phi_{n}v_{l,m}} & {{- \phi_{p_{1}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {\phi_{p_{2}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{2}}}\phi_{n}v_{l,m}} & {{- \phi_{p_{2}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}} & {\phi_{p_{3}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{3}}}\phi_{n}v_{l,m}} & {{- \phi_{p_{3}}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}}$Similarly, for Codebook-Config=2, and N_(g)=2, instead of jointreporting of p₂ and p₃ using i_(1,4), CSI is reported separately usingindices (i_(1,4,1), i_(1,4,2)) or (i _(1,4), i_(1,5)) for (p₂, p₃), andinstead of joint reporting of n₁, n₂, and n₃ using i₂, CSI is reportedseparately using indices (i_(2,1), i_(2,2), i_(2,3)) or (i₂, i₃, i₄) for(n₁, n₂, n₃). The codebook tables for 1-4 layers are shown in TABLES20-23.

TABLE 20 Codebook for 1-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i_(2,1) i_(2,2) i_(2,3) 0,1, . . . , 0,1, . . . ,0,1,2,3 0,1,2,3 0,1,2,3 0,1 0,1 W_(i) _(1,1) _(,i) _(1,2) ^(,) _(i)_(1,4,1) _(,i) _(1,4,2) _(,i) _(2,1) _(,i) _(2,2) _(,i) _(2,3) ⁽¹⁾ N₁O₁− 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,m,p_{2},p_{3},n_{1},n_{2},n_{3}}^{(1)}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}}\end{bmatrix}}$

TABLE 21 Codebook for 2-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i_(2,1) i_(2,2) i_(2,3) 0,1, . . . , 0,1, . . . ,0,1,2,3 0,1,2,3 0,1 0,1 0,1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i)_(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4,1) _(,i) _(1,4,2) _(,i) _(2,1)_(,i) _(2,2) _(,i) _(2,3) ⁽²⁾ N₁O₁ − 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p_{2},p_{3},n_{1},n_{2},n_{3}}^{(2)}} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {{- \phi_{n_{1}}}v_{l^{\prime}m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}$

TABLE 22 Codebook for 3-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i_(2,1) i_(2,2) i_(2,3) 0,1, . . . , 0,1, . . . ,0,1,2,3 0,1,2,3 0,1 0,1 0,1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i)_(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4,1) _(,i) _(1,4,2) _(,i) _(2,1)_(,i) _(2,2) _(,i) _(2,3) ⁽³⁾ N₁O₁ − 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p_{2},p_{3},n_{1},n_{2},n_{3}}^{(3)}} = {\frac{1}{\sqrt{3P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n_{1}}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} & {a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{3}}}b_{n_{3}}v_{l,m}}\end{bmatrix}}$

TABLE 23 Codebook for 4-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i_(2,1) i_(2,2) i_(2,3) 0,1, . . . , 0,1, . . . ,0,1,2,3 0,1,2,3 0,1 0,1 0,1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i)_(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4,1) _(,i) _(1,4,2) _(,i) _(2,1)_(,i) _(2,2) _(,i) _(2,3) ⁽⁴⁾ N₁O₁ − 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p_{2},p_{3},n_{1},n_{2},n_{3}}^{(4)}} = {\frac{1}{\sqrt{4\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n_{1}}}v_{l,m}} & {{- \phi_{n_{1}}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} & {a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{3}}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}$

In another alternative, for Codebook-Config=2, and N_(g)=2 , instead ofjoint reporting of p₂ and p₃ using i_(1,4), CSI is reported separatelyusing indices (i_(1,4,1), i_(1,4,2)) or (i_(1,4), i_(1,5)) for (p₂, p₃),and n₁, n₂, and n₃ are reported jointly using i₂. The codebook tablesfor 1-4 layers are shown in TABLES 24-27.

TABLE 24 Codebook for 1-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i₂ 0,1, . . . , 0,1, . . . , 0,1,2,3 0,1,2,3 0, . .. ,15 W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4,1) _(,i) _(1,4,2) _(,i) ₂⁽¹⁾ N₁O₁ − 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,m,p_{2},p_{3},n}^{(1)}} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}}\end{bmatrix}}\text{;}\mspace{11mu} n_{1}} = {{\left\lfloor \frac{n}{4} \right\rfloor \text{;}\mspace{11mu} n_{2}} = {{\left\lfloor \frac{n}{2} \right\rfloor \mspace{14mu} {mod}\mspace{14mu} 2\text{;}\mspace{11mu} n_{3}} = {n\mspace{14mu} {mod}\mspace{14mu} 2\text{;}}}}}$

TABLE 25 Codebook for 2-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i₂ 0,1, . . . , 0,1, . . . , 0,1,2,3 0,1,2,3 0, . .. ,7 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(+k) ₂ _(,i)_(1,4,1) _(,i) _(1,4,2) _(,i) ₂ ⁽²⁾ N₁O₁ − 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p_{2},p_{3},n}^{(2)}} = {{{\frac{1}{\sqrt{2\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}\text{;}\mspace{11mu} n_{1}} = {{\left\lfloor \frac{n}{4} \right\rfloor \text{;}\mspace{11mu} n_{2}} = {{\left\lfloor \frac{n}{2} \right\rfloor \mspace{14mu} {mod}\mspace{14mu} 2\text{;}\mspace{11mu} n_{3}} = {n\mspace{14mu} {mod}\mspace{14mu} 2\text{;}}}}}$

TABLE 26 Codebook for 3-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i₂ 0,1, . . . , 0,1, . . . , 0,1,2,3 0,1,2,3 0, . .. ,7 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4,1) _(,i) _(1,4,2) _(,i) ₂ ⁽³⁾ N₁O₁ − 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p_{2},p_{3},n}^{(3)}} = {{{\frac{1}{\sqrt{3\; P_{{CSI} - {RS}}}}\left\lbrack {\begin{matrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{matrix}\begin{matrix}v_{l,m} \\{{- \phi_{n_{1}}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{{- a_{p_{3}}}b_{n_{3}}v_{l,m}}\end{matrix}} \right\rbrack}\text{;}\mspace{11mu} n_{1}} = {{\left\lfloor \frac{n}{4} \right\rfloor \text{;}\mspace{11mu} n_{2}} = {{\left\lfloor \frac{n}{2} \right\rfloor \mspace{14mu} {mod}\mspace{14mu} 2\text{;}\mspace{11mu} n_{3}} = {n\mspace{14mu} {mod}\mspace{14mu} 2\text{;}}}}}$

TABLE 27 Codebook for 4-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2)i_(1,4,1) i_(1,4,2) i₂ 0,1, . . . , 0,1, . . . , 0,1,2,3 0,1,2,3 0, . .. ,7 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4,1) _(,i) _(1,4,2) _(,i) ₂ ⁽⁴⁾ N₁O₁ − 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p_{2},p_{3},n}^{(4)}} = {{{\frac{1}{\sqrt{4\; P_{{CSI} - {RS}}}}\left\lbrack {\begin{matrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{matrix}\begin{matrix}v_{l,m} \\{{- \phi_{n_{1}}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{{- a_{p_{3}}}b_{n_{3}}v_{l,m}}\end{matrix}\begin{matrix}v_{l^{\prime},m^{\prime}} \\{{- \phi_{n_{1}}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{matrix}} \right\rbrack}\text{;}\mspace{11mu} n_{1}} = {{\left\lfloor \frac{n}{4} \right\rfloor \text{;}\mspace{11mu} n_{2}} = {{\left\lfloor \frac{n}{2} \right\rfloor \mspace{14mu} {mod}\mspace{14mu} 2\text{;}\mspace{11mu} n_{3}} = {n\mspace{14mu} {mod}\mspace{14mu} 2\text{;}}}}}$

In another alternative, for Codebook-Config=2, and N_(g)=2, p₂ and p₃are reported jointly using i_(1,4), and instead of joint reporting ofn₁, n₂, and n₃ using i₂, CSI is reported separately using indices(i_(2,1), i_(2,2), i_(2,3)) or (i₂, i₃, i₄) for (n₁, n₂, n₃). Thecodebook tables for 1-4 layers are shown in TABLE 28-31.

TABLE 28 Codebook for 1-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i_(2,1) i_(2,2) i_(2,3) 0,1, . . . , 0,1, . . . , 0, . . . ,15 0,1,2,30,1 0,1 W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,i) _(2,1) _(,i) _(2,2)_(,i) _(2,3) ⁽¹⁾ N₁O₁ − 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,m,p,n_{1},n_{2},n_{3}}^{(1)}} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}}\end{bmatrix}}\text{;}\mspace{11mu} p_{2}} = {{\left\lfloor \frac{p}{4} \right\rfloor \text{;}\mspace{11mu} p_{3}} = p}}$

TABLE 29 Codebook for 2-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i_(2,1) i_(2,2) i_(2,3) 0,1, . . . , 0,1, . . . , 0, . . . ,15 0,1 0,10,1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,i) _(2,1) _(,i) _(2,2) _(,i) _(2,3) ⁽²⁾ N₁O₁ − 1 N₂O₂ −1${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n_{1},n_{2},n_{3}}^{(2)}} = {{{\frac{1}{\sqrt{2\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {{- \phi_{n_{1}}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}\text{;}\mspace{11mu} p_{2}} = {{\left\lfloor \frac{p}{4} \right\rfloor \text{;}\mspace{11mu} p_{3}} = p}}$

TABLE 30 Codebook for 3-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i_(2,1) i_(2,2) i_(2,3) 0,1, . . . , 0,1, . . . , 0, . . . ,15 0,1 0,10,1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,i) _(2,1) _(,i) _(2,2) _(,i) _(2,3) ⁽³⁾ N₁O₁ − 1 N₂O₂ −1${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n_{1},n_{2},n_{3}}^{(3)}} = {{{\frac{1}{\sqrt{3\; P_{{CSI} - {RS}}}}\left\lbrack {\begin{matrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{matrix}\begin{matrix}v_{l,m} \\{{- \phi_{n_{1}}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{{- a_{p_{3}}}b_{n_{3}}v_{l,m}}\end{matrix}} \right\rbrack}\text{;}\mspace{11mu} p_{2}} = {{\left\lfloor \frac{p}{4} \right\rfloor \text{;}\mspace{11mu} p_{3}} = p}}$

TABLE 31 Codebook for 4-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i_(2,1) i_(2,2) i_(2,3) 0,1, . . . , 0, . . . , 0, . . . ,15 0,1 0,1 0,1W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,i) _(2,1) _(,i) _(2,2) _(,i) _(2,3) ⁽⁴⁾ N₁O₁ − 1 N₂O₂ −1${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p_{2},p_{3}}^{(4)}} = {{{\frac{1}{\sqrt{4\; P_{{CSI} - {RS}}}}\left\lbrack {\begin{matrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{matrix}\begin{matrix}v_{l,m} \\{{- \phi_{n_{1}}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{{- a_{p_{3}}}b_{n_{3}}v_{l,m}}\end{matrix}\begin{matrix}v_{l^{\prime},m^{\prime}} \\{{- \phi_{n_{1}}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{matrix}} \right\rbrack}\text{;}\mspace{11mu} p_{2}} = {{\left\lfloor \frac{p}{4} \right\rfloor \text{;}\mspace{11mu} p_{3}} = p}}$

In another alternative, for Codebook-Config=2, and N_(g)=2, codebooktables for 1-4 layers are shown in TABLES 32-35.

TABLE 32 Codebook for 1-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i₂  0  1 0,1, . . . , 0,1, . . . , 0, . . .,15 W_(i) _(1,1) _(,i) _(1,2)_(,i) _(1,4) _(,0,0,0) ⁽¹⁾ W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4)_(,0,0,1) ⁽¹⁾ N₁O₁ − 1 N₂O₂ − 1 i_(1,1) i_(1,2) i_(1,4) i₂  2  3 0,1, .. . , 0,1, . . . , 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4)_(,0,1,0) ⁽¹⁾ W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,0,1,1) ⁽¹⁾ N₁O₁− 1 N₂O₂ − 1 i_(1,1) i_(1,2) i_(1,4) i₂  4  5 0,1, . . . , 0,1, . . . ,0, . . . ,15 W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,1,0,0) ⁽¹⁾ W_(i)_(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,1,0,1) ⁽¹⁾ N₁O₁ − 1 N₂O₂ − 1 i_(1,1)i_(1,2) i_(1,4) i₂  6  7 0,1, . . . , 0,1, . . . , 0, . . . ,15 W_(i)_(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,1,1,0) ⁽¹⁾ W_(i) _(1,1) _(,i) _(1,2)_(,i) _(1,4) _(,1,1,1) ⁽¹⁾ N₁O₁ − 1 N₂O₂ − 1 i_(1,1) i_(1,2) i_(1,4) i₂ 8  9 0,1, . . . , 0,1, . . . , 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,2)_(,i) _(1,4) _(,2,0,0) ⁽¹⁾ W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4)_(,2,0,1) ⁽¹⁾ N₁O₁ − 1 N₂O₂ − 1 i_(1,1) i_(1,2) i_(1,4) i₂ 10 11 0,1, .. . , 0,1, . . . , 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4)_(,2,1,0) ⁽¹⁾ W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,2,1,1) ⁽¹⁾ N₁O₁− 1 N₂O₂ − 1 i_(1,1) i_(1,2) i_(1,4) i₂ 12 13 0,1, . . . , 0,1, . . . ,0, . . . ,15 W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,3,0,0) ⁽¹⁾ W_(i)_(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,3,0,1) ⁽¹⁾ N₁O₁ − 1 N₂O₂ − 1 i_(1,1)i_(1,2) i_(1,4) i₂ 14 15 0,1, . . . , 0,1, . . . , 0, . . . ,15 W_(i)_(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,3,1,0) ⁽¹⁾ W_(i) _(1,1) _(,i) _(1,2)_(,i) _(1,4) _(,3,1,1) ⁽¹⁾ N₁O₁ − 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,m,p,n_{1},n_{2},n_{3}}^{(1)}} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}}\end{bmatrix}}\text{;}\mspace{11mu} p_{2}} = {{\left\lfloor \frac{p}{4} \right\rfloor \text{;}\mspace{11mu} p_{3}} = p}}$

TABLE 33 Codebook for 2-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i₂ 0 1 0,1, . . . , 0,1, . . . , 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,1)_(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,0,0,0) ⁽²⁾W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,0,0,1) ⁽²⁾ N₁O₁ − 1 N₂O₂ − 1 i_(1,1) i_(1,2) i_(1,4) i₂2 3 0,1, . . . , 0,1, . . . , 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,1)_(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,0,1,0) ⁽²⁾W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,0,1,1) ⁽²⁾ N₁O₁ − 1 N₂O₂ − 1 i_(1,1) i_(1,2) i_(1,4) i₂4 5 0,1, . . . , 0,1, . . . , 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,1)_(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) ,_(1,0,0) ⁽²⁾W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,1,0,1) ⁽²⁾ N₁O₁ − 1 N₂O₂ − 1 i_(1,1) i_(1,2) i_(1,4) i₂6 7 0,1, . . . , 0,1, . . . , 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,1)_(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,1,1,0) ⁽²⁾W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,1,1,1) ⁽²⁾ N₁O₁ − 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n_{1},n_{2},n_{3}}^{(2)}} = {{{\frac{1}{\sqrt{2\; P_{{CSI} - {RS}}}}\left\lbrack {\begin{matrix}v_{l,m} \\{\phi_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}}\end{matrix}\begin{matrix}v_{l^{\prime},m^{\prime}} \\{{- \phi_{n_{1}}}v_{1^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{matrix}} \right\rbrack}\text{;}\mspace{11mu} p_{2}} = {{\left\lfloor \frac{p}{4} \right\rfloor \text{;}\mspace{11mu} p_{3}} = p}}$

TABLE 34 Codebook for 3-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i₂ 0 1 0,1, . . . , 0,1, . . . , 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,1)_(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(, i) _(1,4) _(,0,0,0) ⁽³⁾W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,0,0,1) ⁽³⁾ N₁O₁ − 1 N₂O₂ − 1 i_(1,1) i_(1,2) i_(1,4) i₂2 3 0,1, . . . , 0,1, . . . , 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,1)_(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,0,1,0) ⁽³⁾W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,0,1,1) ⁽³⁾ N₁O₁ − 1 N₂O₂ − 1 i_(1,1) i_(1,2) i_(1,4) i₂4 5 0,1, . . . , 0,1, . . . , 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,1)_(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,1,0,0) ⁽³⁾W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,1,0,1) ⁽³⁾ N₁O₁ − 1 N₂O₂ − 1 i_(1,1) i_(1,2) i_(1,4) i₂6 7 0,1, . . . , 0,1, . . . , 0, . . . ,15 W_(i) _(1,1) _(,i) _(1,1)_(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,1,1,0) ⁽³⁾W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,1,1,1) ⁽³⁾ N₁O₁ − 1 N₂O₂ − 1${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n_{1},n_{2},n_{3}}^{(3)}} = {{{\frac{1}{\sqrt{3\; P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n_{1}}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} & {a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{3}}}b_{n_{3}}v_{l,m}}\end{bmatrix}}\text{;}\mspace{11mu} p_{2}} = {{\left\lfloor \frac{p}{4} \right\rfloor \text{;}\mspace{11mu} p_{3}} = p}}$

TABLE 35 Codebook for 4-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 2 i₂ i_(1,1) i_(1,2)i_(1,4) 0 1 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 15W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊ _(k) ₂_(,i) _(1,4) _(,0,0,0) ⁽⁴⁾ W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i)_(1,2) _(,i) _(1,2) ₊ _(k) ₂ _(,i) _(1,4) _(,0,0,1) ⁽⁴⁾ i₂ i_(1,1)i_(1,2) i_(1,4) 2 3 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . .. , 15 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊_(k) ₂ _(,i) _(1,4) _(,0,1,0) ⁽⁴⁾ W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁_(,i) _(1,2) _(,i) _(1,2) ₊ _(k) ₂ _(,i) _(1,4) _(,0,1,1) ⁽⁴⁾ i₂ i_(1,1)i_(1,2) i_(1,4) 4 5 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . .. , 15 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊_(k) ₂ _(,i) _(1,4) _(,1,0,0) ⁽⁴⁾ W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁_(,i) _(1,2) _(,i) _(1,2) ₊ _(k) ₂ _(,i) _(1,4) _(,1,0,1) ⁽⁴⁾ i₂ i_(1,1)i_(1,2) i_(1,6) 6 7 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . .. , 15 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊_(k) ₂ _(,i) _(1,4) _(,1,1,0) ⁽⁴⁾ W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁_(,i) _(1,2) _(,i) _(1,2) ₊ _(k) ₂ _(,i) _(1,4) _(,1,1,1) ⁽⁴⁾${{{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n_{1},n_{2},n_{3}}^{(4)}} = {\frac{1}{\sqrt{4P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n_{1}}}v_{l,m}} & {{- \phi_{n_{1}}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} & {a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{3}}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};$${p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p}$

In one embodiment 12C, for Codebook-Config=1 and N_(g)=2, the pre-codingvector/matrix for 1-4 layer CSI reporting is given by one of thefollowing alternative equations. In one example of 1-layer,

$\begin{matrix}{W_{l,m,p,n}^{(1)} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{p}v_{l,m}} \\{\phi_{n}v_{l,m}} \\{\phi_{p}\phi_{n}x_{l,m}}\end{bmatrix}}\mspace{14mu} {and}}} & {{equation}\mspace{14mu} 1} \\{{W_{l,m,p,n}^{(1)} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}x_{l,m,n} \\{\phi_{p}x_{l,m,n}}\end{bmatrix}}}{{{where}\mspace{14mu} x_{l,m,n}} = {\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}}\end{bmatrix}.}}} & {{equation}\mspace{14mu} 2}\end{matrix}$

In one example of 2-layer,

$\begin{matrix}{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} \\{\phi_{n}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p}\phi_{n}v_{l,m}} & {{- \phi_{p}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}}{and}} & {{equation}\mspace{14mu} 1} \\{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}x_{l,l^{\prime},m,m^{\prime},n} \\{\phi_{p}x_{l,l^{\prime},m,m^{\prime},n}}\end{bmatrix}}}{{{where}\mspace{14mu} x_{l,l^{\prime},m,m^{\prime},n}} = {\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}.}}} & {{equation}\mspace{14mu} 2}\end{matrix}$

In one example of 3-layer,

$\begin{matrix}{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} & {\phi_{p}v_{l,m}} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} \\{\phi_{p}\phi_{n}v_{l,m}} & {\phi_{p}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p}}\phi_{n}v_{l,m}}\end{bmatrix}}}{and}} & {{equation}\mspace{14mu} 1} \\{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3P_{{CSI} - {RS}}}}\begin{bmatrix}x_{l,l^{\prime},m,m^{\prime},n} \\{\phi_{p}x_{l,l^{\prime},m,m^{\prime},n}}\end{bmatrix}}}{{{where}\mspace{14mu} x_{l,l^{\prime},m,m^{\prime},n}} = {\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}}\end{bmatrix}.}}} & {{equation}\mspace{14mu} 2}\end{matrix}$

In one example of 4-layer,

$\begin{matrix}{W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} & {\phi_{p}v_{l,m}} & {\phi_{p}v_{l^{\prime},m^{\prime}}} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p}\phi_{n}v_{l,m}} & {\phi_{p}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p}}\phi_{n}v_{l,m}} & {{- \phi_{p}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}\mspace{79mu} {and}}}}} & {{equation}\mspace{14mu} 1} \\{\mspace{79mu} {{W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4P_{{CSI} - {RS}}}}\begin{bmatrix}x_{l,l^{\prime},m,m^{\prime},n} \\{\phi_{p}x_{l,l^{\prime},m,m^{\prime},n}}\end{bmatrix}}}{{{where}\mspace{14mu} x_{l,l^{\prime},m,m^{\prime},n}} = {\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}.}}}} & {{equation}\mspace{14mu} 2}\end{matrix}$

In one embodiment 12D, for Codebook-Config=1 and N_(g)=4, the pre-codingvector/matrix for 1-4 layer CSI reporting is given by one of thefollowing alternative equations. In one example of 1-layer,

$\begin{matrix}{W_{l,m,p,n}^{(1)} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}x_{l,m}} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}}\end{bmatrix}}\mspace{14mu} {and}}} & {{equation}\mspace{14mu} 1} \\{{{W_{l,m,p,n}^{(1)} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}x_{l,m,n} \\{\phi_{p_{1}}x_{l,m,n}} \\{\phi_{p_{2}}x_{l,m,n}} \\{\phi_{p_{3}}x_{l,m,n}}\end{bmatrix}}};}{{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p}}{{{where}\mspace{14mu} x_{l,m,n}} = {\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}}\end{bmatrix}.}}} & {{equation}\mspace{14mu} 2}\end{matrix}$

In one example of 2-layer,

$\begin{matrix}{{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}x_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} \\{\phi_{n}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {{- \phi_{p_{1}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {{- \phi_{p_{2}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}\phi_{n}x_{l,m}} & {{- \phi_{p_{3}}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};}\mspace{79mu} {{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p}}\mspace{79mu} {and}} & {{equation}\mspace{14mu} 1} \\{\mspace{79mu} {{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}x_{l,l^{\prime},m,m^{\prime},n} \\{\phi_{p_{1}}x_{l,l^{\prime},m,m^{\prime},n}} \\{\phi_{p_{2}}x_{l,l^{\prime},m,m^{\prime},n}} \\{\phi_{p_{3}}x_{l,l^{\prime},m,m^{\prime},n}}\end{bmatrix}}};}\mspace{20mu} {{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p}}\mspace{20mu} {{{where}\mspace{14mu} x_{l,l^{\prime},m,m^{\prime},n}} = {\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}.}}}} & {{equation}\mspace{14mu} 2}\end{matrix}$

In one example of 3-layer,

$\begin{matrix}{{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}x_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{3}}x_{l,m}} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {\phi_{p_{1}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{1}}}\phi_{n}v_{l,m}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {\phi_{p_{2}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{2}}}\phi_{n}v_{l,m}} \\{\phi_{p_{3}}\phi_{n}x_{l,m}} & {\phi_{p_{3}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{3}}}\phi_{n}x_{l,m}}\end{bmatrix}}};}\mspace{20mu} {{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p}}\mspace{20mu} {and}} & {{equation}\mspace{14mu} 1} \\{\mspace{79mu} {{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3P_{{CSI} - {RS}}}}\begin{bmatrix}x_{l,l^{\prime},m,m^{\prime},n} \\{\phi_{p_{1}}x_{l,l^{\prime},m,m^{\prime},n}} \\{\phi_{p_{2}}x_{l,l^{\prime},m,m^{\prime},n}} \\{\phi_{p_{3}}x_{l,l^{\prime},m,m^{\prime},n}}\end{bmatrix}}};}\mspace{20mu} {{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p}}\mspace{20mu} {{{where}\mspace{14mu} x_{l,l^{\prime},m,m^{\prime},n}} = {\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}}\end{bmatrix}.}}}} & {{equation}\mspace{14mu} 2}\end{matrix}$

In one example of 4-layer,

$\begin{matrix}{W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}x_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} & {\phi_{p_{3}}x_{l,m}} & {\phi_{p_{3}}v_{l^{\prime},m^{\prime}}} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {\phi_{p_{1}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{1}}}\phi_{n}v_{l,m}} & {{- \phi_{p_{1}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {\phi_{p_{2}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{2}}}\phi_{n}v_{l,m}} & {{- \phi_{p_{2}}}\phi_{n}v_{l^{\prime},m^{\prime}}} \\{\phi_{p_{3}}\phi_{n}x_{l,m}} & {\phi_{p_{3}}\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{p_{3}}}\phi_{n}x_{l,m}} & {{- \phi_{p_{3}}}\phi_{n}v_{l^{\prime},m^{\prime}}}\end{bmatrix};\mspace{20mu} {p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = {p\mspace{79mu} {and}}}}}}} & {{equation}\mspace{14mu} 1} \\{\mspace{79mu} {{{W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4P_{{CSI} - {RS}}}}\begin{bmatrix}x_{l,l^{\prime},m,m^{\prime},n} \\{\phi_{p_{1}}x_{l,l^{\prime},m,m^{\prime},n}} \\{\phi_{p_{2}}x_{l,l^{\prime},m,m^{\prime},n}} \\{\phi_{p_{3}}x_{l,l^{\prime},m,m^{\prime},n}}\end{bmatrix}}};}\mspace{20mu} {{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p}}{{{where}\mspace{14mu} x_{l,l^{\prime},m,m^{\prime},n}} = {\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n}}v_{l,m}} & {{- \phi_{n}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}.}}}} & {{equation}\mspace{14mu} 2}\end{matrix}$

In one embodiment 12E, for Codebook-Config=2 and N_(g)=2, the pre-codingvector/matrix for 1-4 layer CSI reporting is given by one of thefollowing alternative equations:

${{1\text{-}{layer}\text{:}\mspace{14mu} W_{l,m,p,n}^{(1)}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}x_{l,m,n} \\{a_{p_{2}}b_{n_{2}}x_{l,m,n}} \\{\phi_{n_{1}}x_{l,m,n}} \\{a_{p_{3}}b_{n_{3}}x_{l,m,n}}\end{bmatrix}}}\mspace{11mu};$${p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p};{n_{1} = \left\lfloor \frac{n}{4} \right\rfloor};{n_{2} = \left\lfloor \frac{n}{2} \right\rfloor}$

mod 2;n₃=n mod 2;

${{2\text{-}{layer}\mspace{11mu} \text{:}\mspace{11mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{\phi_{n_{1}},v_{l,m}} & {{- \phi_{n_{1}}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p};$${{3\text{-}{layer}\mspace{11mu} \text{:}\mspace{11mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)}} = {\frac{1}{\sqrt{3P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} & {a_{p_{2}}b_{n_{2}}v_{l,m}} \\{\phi_{n_{1}},v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n_{1}}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{3}}}b_{n_{3}}v_{l,m}}\end{bmatrix}}};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p};{n_{1} = \left\lfloor \frac{n}{4} \right\rfloor};{n_{2} = \left\lfloor \frac{n}{2} \right\rfloor}$

mod 2; n₃=n mod 2; and

${{4\text{-}{layer}\mspace{11mu} \text{:}\mspace{11mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)}} = {\frac{1}{\sqrt{4P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} & {a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{\phi_{n_{1}},v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n_{1}}}v_{l,m}} & {{- \phi_{n_{1}}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{3}}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p};{n_{1} = \left\lfloor \frac{n}{4} \right\rfloor};{n_{2} = \left\lfloor \frac{n}{2} \right\rfloor}$

mod 2; n₃=n mod 2;.

In one embodiment 12F, the four codebook indicesi_(1,1),i_(1,2),i_(1,3), and i₂ for 1-layer CSI reporting are reportedas two PMIs: the first PMI i₁ comprising three components, i.e.,i₁=(i_(1,1),i_(1,2),i_(1,4)); and the second PMI i₂.

Similarly, the five codebook indices i_(1,1),i_(1,2),i_(1,3), i_(1,4),and i₂ for 2, 3, or 4-layer CSI reporting are reported as two PMIs: thefirst PMI i₁ comprising four components, i.e.,i₁=(i_(1,1),i_(1,2),i_(1,3),i_(1,4)); and the second PMI i₂.

In one embodiment 12G, the codebook index i_(1,4) is reported as aseparate (third) PMI i₃ for inter-panel co-phase. The 1-layer CSI isreported as three PMIs: the first PMI i₁ comprising two components,i.e., i₁=(i_(1,1),i_(1,2)); the second PMI i₂; and the third PMIi₃=i_(1,4).

Similarly, the 2, 3, or 4-layer CSI is reported as three PMIs: the firstPMI i₁ comprising three components, i.e., i₁=(i_(1,1), i_(1,2),i_(1,3));the second PMI i₂; and the third PMI i₃=i_(1,4).

For Codebook-Config=1, the inter-panel co-phase φ_(p) for N_(g)=2 and(φ_(p) ₁ ,φ_(p) ₂ ,φ_(p) ₃ ) for N_(g)=4 is reported using the third PMIi₃ in a WB manner. For Codebook-Config=2, the inter-panel co-phase hastwo components: (φ_(p) ₂ ,φ_(p) ₃ ) reported in WB manner and (φ_(n) ₂,φ_(n) ₃ ) reported in a SB manner. The WB and SB components arereported according to at least one of the following alternatives. In oneexample of Alt 12G-0, the third PMI has two components, i.e.,i₃=(i_(3,1),i_(3,2)), where the component i_(3,1) is reported in a WBmanner to indicate (φ_(p) ₂ ,φ_(p) ₃ ) and the component i_(3,2) isreported in a SB manner to indicate (φ_(n) ₂ ,φ_(n) ₃ ).

In one example of Alt 12G-1, the third PMI i₃ indicates the WB component(φ_(p) ₂ ,φ_(p) ₃ ), and the SB component (φ_(n) ₂ ,φ_(n) ₃ ) isreported using the second PMI i₂. In one example of Alt 2, the third PMIi₃ indicates the WB component (φ_(p) ₂ ,φ_(p) ₃ ), and the SB component(φ_(n) ₂ ,φ_(n) ₃ ) is reported using a separate fourth PMI i₄. In oneexample of Alt 12G-3, the third PMI i₃ indicates the WB component (φ_(p)₂ ,φ_(p) ₃ ), and the SB component (φ_(n) ₂ ,φ_(n) ₃ ) is reported usingthe second component i_(2,2) of the second PMI i₂=(i_(2,1),i_(2,2)),where the first component i_(2,1) indicates the SB co-phase φ_(n) ₁ .

In one embodiment 12H, the codebook indices i_(1,3) and i_(1,4) in thecodebook tables in the present disclosure are swapped. That is, i_(1,4)indicates the mapping to k₁ and k₂ in TABLE 6 and TABLE 7, and i_(1,3)indicates the WB inter-panel co-phase: φ_(p) for Codebook-Config=1,N_(g)=2; (φ_(p) ₁ ,φ_(p) ₂ , φ_(p) ₃ ) for Codebook-Config=1,N_(g)=4;and (φ_(p) ₂ ,φ_(p) ₃ ) for Codebook-Config=2, N_(g)=2.

In one embodiment 121, the codebook table for Codebook-Config=2, N_(g)=4is given by TABLES 36-39.

TABLE 36 Codebook for 1-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 4 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 4095 0, . .. , 255 W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,i) ₂ ⁽¹⁾${{{where}\mspace{14mu} W_{l,m,p,n}^{(1)}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}} \\{a_{p_{7}}b_{n_{7}}v_{l,m}}\end{bmatrix}}};$${p_{2} = \left\lfloor \frac{p}{1024} \right\rfloor};{p_{3} = \left\lfloor \frac{p}{256} \right\rfloor};{p_{4} = \left\lfloor \frac{p}{64} \right\rfloor};{p_{5} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{6} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{7} = p};$${n_{1} = \left\lfloor \frac{n}{64} \right\rfloor};{n_{2} = {\left\lfloor \frac{n}{32} \right\rfloor {mod}\mspace{14mu} 2}};{n_{3} = {\left\lfloor \frac{n}{16} \right\rfloor {mod}\mspace{14mu} 2}};{n_{4} = {\left\lfloor \frac{n}{8} \right\rfloor {mod}\mspace{14mu} 2}};{n_{5} = {\left\lfloor \frac{n}{4} \right\rfloor {mod}\mspace{14mu} 2}};\; {n_{6} = {\left\lfloor \frac{n}{2} \right\rfloor {mod}\mspace{14mu} 2}};{n_{7} = {n\mspace{14mu} {mod}\mspace{14mu} 2}};$

TABLE 37 Codebook for 2-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 4 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 4095 0, . .. , 127 W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊_(k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽²⁾${{{w{here}}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {{- \phi_{n_{1}}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} & {a_{p_{4}}b_{n_{4}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} & {{- a_{p_{5}}}b_{n_{5}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}} & {a_{p_{6}}b_{n_{6}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{7}}b_{n_{7}}v_{l,m}} & {{- a_{p_{7}}}b_{n_{7}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};$${p_{2} = \left\lfloor \frac{p}{1024} \right\rfloor};{p_{3} = \left\lfloor \frac{p}{256} \right\rfloor};{p_{4} = \left\lfloor \frac{p}{64} \right\rfloor};{p_{5} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{6} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{7} = p};$${n_{1} = \left\lfloor \frac{n}{64} \right\rfloor};{n_{2} = {\left\lfloor \frac{n}{32} \right\rfloor {mod}\mspace{14mu} 2}};{n_{3} = {\left\lfloor \frac{n}{16} \right\rfloor {mod}\mspace{14mu} 2}};{n_{4} = {\left\lfloor \frac{n}{8} \right\rfloor {mod}\mspace{14mu} 2}};{n_{5} = {\left\lfloor \frac{n}{4} \right\rfloor {mod}\mspace{14mu} 2}};\; {n_{6} = {\left\lfloor \frac{n}{2} \right\rfloor {mod}\mspace{14mu} 2}};{n_{7} = {n\mspace{14mu} {mod}\mspace{14mu} 2}};$

TABLE 38 Codebook for 3-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 4 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 4095 0, . .. , 127 W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊_(k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽³⁾${{{w{here}}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n_{1}}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} & {a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{3}}}b_{n_{3}}v_{l,m}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} & {a_{p_{4}}b_{n_{4}}v_{l^{\prime},m^{\prime}}} & {a_{p_{4}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} & {a_{p_{5}}b_{n_{5}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{5}}}b_{n_{5}}v_{l,m}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}} & {a_{p_{6}}b_{n_{6}}v_{l^{\prime},m^{\prime}}} & {a_{p_{6}}b_{n_{6}}v_{l,m}} \\{a_{p_{7}}b_{n_{7}}v_{l,m}} & {a_{p_{7}}b_{n_{7}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{7}}}b_{n_{7}}v_{l,m}}\end{bmatrix}}};$${p_{2} = \left\lfloor \frac{p}{1024} \right\rfloor};{p_{3} = \left\lfloor \frac{p}{256} \right\rfloor};{p_{4} = \left\lfloor \frac{p}{64} \right\rfloor};{p_{5} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{6} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{7} = p};$${n_{1} = \left\lfloor \frac{n}{64} \right\rfloor};{n_{2} = {\left\lfloor \frac{n}{32} \right\rfloor {mod}\mspace{14mu} 2}};{n_{3} = {\left\lfloor \frac{n}{16} \right\rfloor {mod}\mspace{14mu} 2}};{n_{4} = {\left\lfloor \frac{n}{8} \right\rfloor {mod}\mspace{14mu} 2}};{n_{5} = {\left\lfloor \frac{n}{4} \right\rfloor {mod}\mspace{14mu} 2}};\; {n_{6} = {\left\lfloor \frac{n}{2} \right\rfloor {mod}\mspace{14mu} 2}};{n_{7} = {n\mspace{14mu} {mod}\mspace{14mu} 2}};$

TABLE 39 Codebook for 4-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 2, N_(g) = 4 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 4095 0, . .. , 127 W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊_(k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽⁴⁾${{{w{here}}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)}} = {\frac{1}{\sqrt{4P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l^{\prime},m^{\prime}} & v_{l,m} & v_{l^{\prime},m^{\prime}} \\{\phi_{n_{1}}v_{l,m}} & {\phi_{n_{1}}v_{l^{\prime},m^{\prime}}} & {{- \phi_{n_{1}}}v_{l,m}} & {{- \phi_{n_{1}}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} & {a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {a_{p_{3}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{3}}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} & {a_{p_{4}}b_{n_{4}}v_{l^{\prime},m^{\prime}}} & {a_{p_{4}}b_{n_{4}}v_{l,m}} & {a_{p_{4}}b_{n_{4}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} & {a_{p_{5}}b_{n_{5}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{5}}}b_{n_{5}}v_{l,m}} & {{- a_{p_{5}}}b_{n_{5}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}} & {a_{p_{6}}b_{n_{6}}v_{l^{\prime},m^{\prime}}} & {a_{p_{6}}b_{n_{6}}v_{l,m}} & {a_{p_{6}}b_{n_{6}}v_{l^{\prime},m^{\prime}}} \\{a_{p_{7}}b_{n_{7}}v_{l,m}} & {a_{p_{7}}b_{n_{7}}v_{l^{\prime},m^{\prime}}} & {{- a_{p_{7}}}b_{n_{7}}v_{l,m}} & {{- a_{p_{7}}}b_{n_{7}}v_{l^{\prime},m^{\prime}}}\end{bmatrix}}};$${p_{2} = \left\lfloor \frac{p}{1024} \right\rfloor};{p_{3} = \left\lfloor \frac{p}{256} \right\rfloor};{p_{4} = \left\lfloor \frac{p}{64} \right\rfloor};{p_{5} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{6} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{7} = p};$${n_{1} = \left\lfloor \frac{n}{64} \right\rfloor};{n_{2} = {\left\lfloor \frac{n}{32} \right\rfloor {mod}\mspace{14mu} 2}};{n_{3} = {\left\lfloor \frac{n}{16} \right\rfloor {mod}\mspace{14mu} 2}};{n_{4} = {\left\lfloor \frac{n}{8} \right\rfloor {mod}\mspace{14mu} 2}};{n_{5} = {\left\lfloor \frac{n}{4} \right\rfloor {mod}\mspace{14mu} 2}};\; {n_{6} = {\left\lfloor \frac{n}{2} \right\rfloor {mod}\mspace{14mu} 2}};{n_{7} = {n\mspace{14mu} {mod}\mspace{14mu} 2}};$

In one embodiment 12J, an alternative 2-layer (rank 2) codebookcomprises of precoding matrices such that the DFT beams for the twolayers are the same, i.e., l=l′,m=m′. In this case, when the number oflayers v=2, each PMI value corresponds to four codebook indicesi_(1,1),i_(1,2),i_(1,4),i₂, similar to the case of v=1. There is no needto have the codebook index i_(1,3) to k₁ and k₂ mapping such as TABLE 6for 2-layer reporting. The 2-layer codebook table is given by TABLE 40.

TABLE 40 Codebook for 2-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Codebook-Config = 1, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 3 0, 1 W_(i)_(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,i) ₂ ⁽²⁾${{{where}\mspace{14mu} W_{l,m,p,n}^{(2)}} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l,m} \\{\phi_{n}v_{l,m}} & {\phi_{n}v_{l,m}} \\{\phi_{p}v_{l,m}} & {\phi_{p}v_{l,m}} \\{\phi_{p}\phi_{n}v_{l,m}} & {\phi_{p}\phi_{n}v_{l,m}}\end{bmatrix}}};$ Codebook-Config = 1, N_(g) = 4 i_(1,1) i_(1,2) i_(1,4)i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 63 0, 1W_(i) _(1,1) _(,i) _(1,2) _(,i) _(1,4) _(,i) ₂ ⁽²⁾${{{w{here}}\mspace{14mu} W_{l,m,p,n}^{(2)}} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l,m} \\{\phi_{n}v_{l,m}} & {{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} & {\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{1}}\phi_{n}v_{l,m}} & {{- \phi_{p_{1}}}\phi_{n}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} & {\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{2}}\phi_{n}v_{l,m}} & {{- \phi_{p_{2}}}\phi_{n}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} & {\phi_{p_{3}}v_{l,m}} \\{\phi_{p_{3}}\phi_{n}v_{l,m}} & {{- \phi_{p_{3}}}\phi_{n}v_{l,m}}\end{bmatrix}}};{p_{1} = \left\lfloor \frac{p}{16} \right\rfloor};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = {p.}}$Codebook-Config = 2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4) i₂ 0, 1, . . . ,N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, . . . , 15 0, . . . , 7 W_(i) _(1,1)_(,i) _(1,2) _(,i) _(1,4) _(,i) ₂ ⁽²⁾${{{w{here}}\mspace{14mu} W_{l,m,p,n}^{(2)}} = {\frac{1}{\sqrt{2P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} & v_{l,m} \\{\phi_{n_{1}}v_{l,m}} & {{- \phi_{n_{1}}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} & {a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} & {{- a_{p_{3}}}b_{n_{3}}v_{l,m}}\end{bmatrix}}};{p_{2} = \left\lfloor \frac{p}{4} \right\rfloor};{p_{3} = p};$${n_{1} = \left\lfloor \frac{n}{4} \right\rfloor};{n_{2} = {\left\lfloor \frac{n}{2} \right\rfloor {mod}\mspace{14mu} 2}};{n_{3} = {n\mspace{14mu} {mod}\mspace{14mu} 2}};$

In one embodiment 12K, the higher layer codebook configuration parameterCodebook-Config in codebook tables in the present disclosure is referredto as Codebook-Mode or Mode. For example, Codebook-Config=1 andCodebook-Config=2 respectively are mapped to Mode 1 and Mode2.

In one embodiment 13, a UE is configured with a PMI codebook for multipanels (N_(g)=M>1) as follows.

For 8 antenna ports (e.g. {15, 16, . . . , 22}), 16 antenna ports (e.g.{15, 16, . . . , 30}), 32 antenna ports (e.g. {15, 16, . . . , 46}), andthe UE configured with higher layer (e.g. RRC) parameterMultiPanelCodebook set to Mode1 or Mode2, each PMI value corresponds tothe codebook indices i₁ and i₂, where i₁ is the vector given by:

$i_{1} = \left\{ \begin{matrix}\left\lbrack i_{1,1} \right. & i_{1,2} & \left. i_{1,4} \right\rbrack & \; & {v = 1} \\\left\lbrack i_{1,1} \right. & i_{1,2} & i_{1,3} & \left. i_{1,4} \right\rbrack & {v \in \left\{ {2,3,4} \right\}}\end{matrix} \right.$

and V is the associated RI value.

The values of N_(g), N₁, and N₂ are configured with the higher-layerparameters CodebookConfig-Ng, CodebookConfig-N1 and CodebookConfig-N2,respectively. The supported configurations of (N_(g),N₁,N₂) for a givennumber of CSI-RS ports and the corresponding values of (O₁,O₂) are givenin TABLE 41. The number of CSI-RS ports, P_(CSI-RS) ports, is2N_(g)N₁N₂. A UE may only use i_(1,2)=0 and may not report i_(1,2) ifthe value of CodebookConfig-N2 is set to 1.

TABLE 41 Supported configurations of (N_(g), N₁, N₂) and (O₁, O₂) Numberof CSI-RS antenna ports, P_(CSI-RS) (N_(g), N₁, N₂) (O₁, O₂)MultiPanelCodebook 8 (2, 2, 1) (4, 1) Mode1, Mode2 16 (2, 4, 1) (4, 1)Mode1, Mode2 (4, 2, 1) (4, 1) Mode1 (2, 2, 2) (4, 4) Mode1, Mode2 32 (2,8, 1) (4, 1) Mode1, Mode2 (4, 4, 1) (4, 1) Mode1 (2, 4, 2) (4, 4) Mode1,Mode2 (4, 2, 2) (4, 4) Mode1

The mapping from i_(1,3) to k₁ and k₂ for 2-layer reporting is given inTABLE 6. The mapping from i_(1,3) to k₁ and k₂ for 3-layer and 4-layerreporting is given in TABLE 7. When MultiPanelCodebook is set to Mode1,i_(1,4) is given by:

$i_{1,4} = \left\{ {\begin{matrix}\; & i_{1,4,1} & \; & {N_{g} = 2} \\\left\lbrack i_{1,4,1} \right. & i_{1,4,2} & \left. i_{1,4,3} \right\rbrack & {N_{g} = 4}\end{matrix}.} \right.$

When MultiPanelCodebook is set to Mode2 (where N_(g)=2), i_(1,4) and i₂are

$\begin{matrix}{i_{1,4} = \left\lbrack \begin{matrix}i_{1,4,1} & \left. i_{1,4,2} \right\rbrack\end{matrix} \right.} \\{i_{2} = \left\lbrack \begin{matrix}\begin{matrix}i_{2,0} & i_{2,1,1}\end{matrix} & \left. i_{2,1,2} \right\rbrack\end{matrix} \right.}\end{matrix}.$

The quantities φ_(n), a_(p), b_(n), u_(m), and v_(l,m) are given by:

ϕ_(n) = e^(j π n/2) a_(p) = e^(j π/4)e^(j π p/2)b_(n) = e^(−j π/4)e^(j π n/2)$u_{m} = \left\{ {{\begin{matrix}\left\lbrack 1 \right. & e^{j\frac{2{\pi m}}{O_{2}N_{2}}} & \cdots & \left. e^{j\frac{2\pi \; {m{({N_{2} - 1})}}}{O_{2}N_{2}}} \right\rbrack & {N_{2} > 1} \\\; & \; & 1 & \; & {N_{2} = 1}\end{matrix}v_{l,m}} = {\begin{bmatrix}u_{m} & {e^{j\frac{2\pi \; l}{O_{1}N_{1}}}u_{m}} & \cdots & {e^{j\frac{2\pi \; {l{({N_{1} - 1})}}}{O_{1}N_{1}}}u_{m}}\end{bmatrix}^{T}.}} \right.$

Furthermore, the quantities W_(l,m,p,n) ^(1,1,N) ^(g) and W_(l,m,p,n)^(1,2,N) ^(g) (N_(g) ∈ {2,4}) are given by:

${\begin{matrix}{W_{l,m,p,n}^{1,1,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}}\end{bmatrix}}} & {W_{l,m,p,n}^{1,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}}\end{bmatrix}}} \\{W_{l,m,p,n}^{1,1,4} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}} & {W_{l,m,p,n}^{1,2,4} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}}\end{matrix}{where}\mspace{14mu} p} = \left\{ {\begin{matrix}\; & p_{1} & \; & {N_{g} = 2} \\\left\lbrack {p_{1},} \right. & p_{2} & \left. p_{3} \right\rbrack & {N_{g} = 4}\end{matrix},{and}} \right.$

the quantities W_(l,m,p,n) ^(2,1,N) ^(g) and W_(l,m,p,n) ^(2,2,N) ^(g)(N_(g)=2) are given by:

$\begin{matrix}{W_{l,m,p,n}^{2,1,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}b_{n_{i}}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}}\end{bmatrix}}} & {W_{l,m,p,n}^{2,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}}\end{bmatrix}}}\end{matrix}{where}\mspace{14mu} {\begin{matrix}{p = \left\lbrack \begin{matrix}p_{1} & \left. p_{2} \right\rbrack\end{matrix} \right.} \\{n = \begin{matrix}\left\lbrack n_{0} \right. & n_{1} & \left. n_{2} \right\rbrack\end{matrix}}\end{matrix}.}$

The codebooks for 1-4 layers are given respectively in TABLES 42-45.

TABLE 42 Codebook for 1-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Mode1, N_(g) ∈ {2, 4} i_(1,1) i_(1,2) i_(1,4,q), q = 1,. . . , N_(g) − 1 i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1,2, 3 0, 1, 2, 3 W_(i) _(1,1), i_(1,2),i_(1,4), i₂.⁽¹⁾ where W_(l,m,p,n)⁽¹⁾ = W_(l,m,p,n) ^(1,1,N) _(g). Mode2, N_(g) = 2 i_(1,1) i_(1,2)i_(1,4,q), q = 1, 2 i_(2,0) i_(2,1,q), q = 1, 2 0, 1, . . . , N₁O₁ − 10, 1, . . . , N₂O₂ − 1 0, 1, 2, 3 0, 1, 2, 3 0, 1 W_(i) _(1,1),i_(1,2),i_(1,4), i₂ ⁽¹⁾ where W_(l,m,p,n) ⁽¹⁾ = W_(l,m,p,n) ^(2,1,N)_(g).

TABLE 43 Codebook for 2-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Mode1, N_(g) ϵ {2, 4} i_(1,1) i_(1,2) i_(1,4,q), q = 1,. . . , N_(g) − 1 i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1,2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊_(k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽²⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {{\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{1,1,N_{g}} & W_{l^{\prime},m^{\prime},p,n}^{1,2,N_{g}}\end{bmatrix}}.}$ Mode2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4,q), q = 1, 2i_(2,0),i_(2,1,q), q = 1, 2 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ −1 0, 1, 2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i)_(1,2) ₊ _(k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽²⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {{\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{2,1,N_{g}} & W_{l^{\prime},m^{\prime},p,n}^{2,2,N_{g}}\end{bmatrix}}.}$

TABLE 44 Codebook for 3-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Mode1, N_(g) ϵ {2, 4} i_(1,1) i_(1,2) i_(1,4,q), q = 1,. . . , N_(g) − 1 i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1,2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊_(k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽³⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)}} = {{\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,1,N_{g}} & \begin{matrix}W_{l^{\prime},m^{\prime},p,n}^{1,1,N_{g}} & W_{l,m,p,n}^{1,2,N_{g}}\end{matrix}\end{bmatrix}}.}$ Mode2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4,q), q = 1, 2i_(2,0),i_(2,1,q), q = 1, 2 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ −1 0, 1, 2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i)_(1,2) ₊ _(k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽³⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)}} = {{\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{2,1,N_{g}} & \begin{matrix}W_{l^{\prime},m^{\prime},p,n}^{2,1,N_{g}} & W_{l,m,p,n}^{2,2,N_{g}}\end{matrix}\end{bmatrix}}.}$

TABLE 45 Codebook for 4-layer CSI reporting using antenna ports [15 to14 + P_(CSI-RS)] Mode1, N_(g) ϵ {2, 4} i_(1,1) i_(1,2) i_(1,4,q), q = 1,. . . , N_(g) − 1 i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1,2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊_(k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽⁴⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)}} = {{\frac{1}{\sqrt{4}}\begin{bmatrix}W_{l,m,p,n}^{1,1,N_{g}} & \begin{matrix}W_{l^{\prime},m^{\prime},p,n}^{1,1,N_{g}} & W_{l,m,p,n}^{1,2,N_{g}} & W_{l^{\prime},m^{\prime},p,n}^{1,2,N_{g}}\end{matrix}\end{bmatrix}}.}$ Mode2, N_(g) = 2 i_(1,1) i_(1,2) i_(1,4,q), q = 1, 2i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1, 2, 3 0, 1 W_(i)_(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊ _(k) ₂ _(,i)_(1,4) _(,i) ₂ ⁽⁴⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)}} = {{\frac{1}{\sqrt{4}}\begin{bmatrix}W_{l,m,p,n}^{2,1,N_{g}} & \begin{matrix}W_{l^{\prime},m^{\prime},p,n}^{2,1,N_{g}} & W_{l,m,p,n}^{2,2,N_{g}} & W_{l^{\prime},m^{\prime},p,n}^{2,2,N_{g}}\end{matrix}\end{bmatrix}}.}$

In one embodiment 13A, the 1-4 layer codebooks for Mode2 givenrespectively in TABLES 42-45 are also supported for N_(g)=4, wherei_(1,4) and i₂ are replaced with the following:

$\begin{matrix}\begin{matrix}{i_{1,4} = \left\{ \begin{matrix}\; & \; & {\; \left\lbrack i_{1,4,1} \right.} & \left. i_{1,4,2} \right\rbrack & \; & \; & {N_{g} = 2} \\\left\lbrack i_{1,4,1} \right. & i_{1,4,2} & i_{1,4,3} & i_{1,4,4} & i_{1,4,5} & \left. i_{1,4,6} \right\rbrack & {N_{g} = 4}\end{matrix} \right.} \\{{i_{1,4,q} \in \left\{ {0,1,2,3} \right\}},{q = 1},\ldots \;,{2\mspace{11mu} \left( {N_{g} - 1} \right)}}\end{matrix} \\\begin{matrix}{i_{2} = \left\{ \begin{matrix}\; & \; & {\; \left\lbrack i_{2,0} \right.} & i_{2,1,1} & {\left. i_{2,1,2} \right\rbrack \;} & \; & \; & {N_{g} = 2} \\\left\lbrack i_{2,0} \right. & i_{2,1,1} & i_{2,1,2} & i_{2,1,3} & i_{2,1,4} & i_{2,1,5} & \left. i_{2,1,6} \right\rbrack & {N_{g} = 4}\end{matrix} \right.} \\{{i_{2,1,q} \in \left\{ {0,1} \right\}},{q = 1},\ldots \;,{2\mspace{11mu} \left( {N_{g} - 1} \right)}}\end{matrix}\end{matrix};$

and the quantities W_(l,m,p,n) ^(2,1,N) ^(g) and W_(l,m,p,n) ^(2,2,N)^(g) for N_(g)=4 are given by:

$\begin{matrix}{W_{l,m,p,n}^{2,1,4} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}}\end{bmatrix}}} & {W_{l,m,p,n}^{2,2,4} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{{- a_{p_{4}}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} \\{{- a_{p_{6}}}b_{n_{6}}v_{l,m}}\end{bmatrix}}}\end{matrix}{where}\mspace{14mu} {\begin{matrix}{p = \left\lbrack \begin{matrix}p_{1} & p_{2} & p_{3} & p_{4} & p_{5} & \left. p_{6} \right\rbrack\end{matrix} \right.} \\{n = \begin{matrix}\left\lbrack n_{0} \right. & n_{1} & n_{2} & n_{3} & n_{4} & n_{5} & \left. n_{6} \right\rbrack\end{matrix}}\end{matrix}.}$

In one embodiment 14, a UE is configured with a PMI codebook for multipanels (N_(g)=M>1) as follows. For 8 antenna ports (e.g. {15, 16, . . ., 22}), 16 antenna ports (e.g. {15, 16, . . . , 30}), 32 antenna ports(e.g. {15, 16, . . . , 46}), and the UE configured with higher layerparameter MultiPanelCodebook set to Mode1 or Mode2, where each PMI valuecorresponds to the codebook indices i₁ and i₂, where i₁ is the vectorgiven by:

$i_{1} = \left\{ \begin{matrix}\left\lbrack i_{1,1} \right. & i_{1,2} & \left. i_{1,4} \right\rbrack & \; & {v = 1} \\\left\lbrack i_{1,1} \right. & i_{1,2} & i_{1,3} & \left. i_{1,4} \right\rbrack & {v \in \left\{ {2,3,4} \right\}}\end{matrix} \right.$

and v is the associated RI value.

The mapping from i_(1,3) to k₁ and k₂ for 2-layer reporting is given inTABLE 6. The mapping from i_(1,3) to k₁ and k₂ for 3-layer and 4-layerreporting is given in TABLE 7. The values of N_(g), N₁, and N₂ areconfigured with the higher-layer parameters CodebookConfig-Ng,CodebookConfig-N1 and CodebookConfig-N2, respectively. The supportedconfigurations of (N_(g),N₁,N₂) for a given number of CSI-RS ports andthe corresponding values of (O₁,O₂) are given in TABLE 41. The number ofCSI-RS ports, P_(CSI-RS), is 2N_(g)N₁N₂. A UE may only use i_(1,2)=0 andmay not report i_(1,2) if the value of CodebookConfig-N2 is set to 1.

When MultiPanelCodebook is set to Mode1, i_(1,4) is

$\begin{matrix}{i_{1,4} = \left\{ \begin{matrix}\; & i_{1,4,1} & \; & {N_{g} = 2} \\\left\lbrack i_{1,4,1} \right. & i_{1,4,2} & \left. i_{1,4,3} \right\rbrack & {N_{g} = 4}\end{matrix} \right.} \\{{i_{1,4,q} \in \left\{ {0,1,2,3} \right\}},\mspace{11mu} {q = 1},2,3}\end{matrix}.$

The quantities φ_(n), u_(m), and v_(l,m) are given by:

ϕ_(n) = e^(−j π/2) $u_{m} = \left\{ {\begin{matrix}\left\lbrack 1 \right. & e^{j\frac{2{\pi m}}{O_{2}N_{2}}} & \cdots & \left. e^{j\frac{2\pi \; {m{({N_{2} - 1})}}}{O_{2}N_{2}}} \right\rbrack & {N_{2} > 1} \\\; & \; & 1 & \; & {N_{2} = 1}\end{matrix}.} \right.$

Furthermore, the quantities W_(l,m,p,n) ^(1,N) ^(g) and W_(l,m,p,n)^(2,N) ^(g) (

$v_{l,m} = \begin{bmatrix}u_{m} & {e^{j\frac{2\pi \; l}{O_{1}N_{1}}}u_{m}} & \cdots & {e^{j\frac{2\pi \; {l{({N_{1} - 1})}}}{O_{1}N_{1}}}u_{m}}\end{bmatrix}^{T}$

$\begin{matrix}{W_{l,m,p,n}^{1,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}}\end{bmatrix}}} & {W_{l,m,p,n}^{2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}}\end{bmatrix}}}\end{matrix}$

N_(g)∈ {2,4}) are given by:

${\begin{matrix}{W_{l,m,p,n}^{1,4} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}} & {W_{l,m,p,n}^{2,4} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}}\end{matrix}{where}\mspace{14mu} p} = \left\{ {\begin{matrix}\; & p_{1} & \; & {N_{g} = 2} \\\left\lbrack {p_{1},} \right. & p_{2} & \left. p_{3} \right\rbrack & {N_{g} = 4}\end{matrix}.} \right.$

The Mode1 codebooks for 1-4 layers are given respectively in TABLES46-49.

TABLE 46 Codebook for Mode1 1-layer CSI reporting using antenna ports[15 to 14 + P_(CSI-RS)] i_(1,1) i_(1,2) i_(1,4,q), q = 1, . . . , N_(g)− 1 i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1, 2, 3 0, 1, 2,3 W_(i) _(1,1), i_(1,2),i_(1,4), i₂ ⁽¹⁾ where W_(l,m,p,n) ⁽¹⁾ =W_(l,m,p,n) ^(1,N) _(g).

TABLE 47 Codebook for Mode1 2-layer CSI reporting using antenna ports[15 to 14 + P_(CSI-RS)] i_(1,1) i_(1,2) i_(1,4,q), q = 1, . . . , N_(g)− 1 i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1, 2, 3 0, 1W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊ _(k) ₂_(,i) _(1,4) _(,i) ₂ ⁽²⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {{\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g}} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g}}\end{bmatrix}}.}$

TABLE 48 Codebook for Mode1 3-layer CSI reporting using antenna ports[15 to 14 + P_(CSI-RS)] i_(1,1) i_(1,2) i_(1,4,q), q = 1, . . . , N_(g)− 1 i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1, 2, 3 0, 1W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊ _(k) ₂_(,i) _(1,4) _(,i) ₂ ⁽³⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)}} = {{\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g}} & \begin{matrix}W_{l^{\prime},m^{\prime},p,n}^{1,N_{g}} & W_{l,m,p,n}^{2,N_{g}}\end{matrix}\end{bmatrix}}.}$

TABLE 49 Codebook for Mode1 4-layer CSI reporting using antenna ports[15 to 14 + P_(CSI-RS)] i_(1,1) i_(1,2) i_(1,4,q), q = 1, . . . , N_(g)− 1 i₂ 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ − 1 0, 1, 2, 3 0, 1W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i) _(1,2) ₊ _(k) ₂_(,i) _(1,4) _(,i) ₂ ⁽⁴⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)}} = {{\frac{1}{\sqrt{4}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g}} & \begin{matrix}W_{l^{\prime},m^{\prime},p,n}^{1,N_{g}} & W_{l,m,p,n}^{2,N_{g}} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g}}\end{matrix}\end{bmatrix}}.}$

When MultiPanelCodebook is set to Mode2 and N_(g)=2, i_(1,4) and i₂ are

$\begin{matrix}{i_{1,4} = \left\lbrack \begin{matrix}i_{1,4,1} & \left. i_{1,4,2} \right\rbrack\end{matrix} \right.} \\{i_{2} = \left\lbrack \begin{matrix}\begin{matrix}i_{2,0} & i_{2,1,1}\end{matrix} & \left. i_{2,1,2} \right\rbrack\end{matrix} \right.}\end{matrix}.$

The quantities a_(p) and b_(n) are given by:

$\begin{matrix}{a_{p} = {e^{j\; \pi \text{/}4}e^{j\; \pi \; p\text{/}2}}} \\{b_{n} = {e^{{- j}\; \pi \text{/}4}e^{j\; \pi \; n\text{/}2}}}\end{matrix}.$

Furthermore, the quantities and W_(l,m,p,n) ^(1,N) ^(g) and W_(l,m,p,n)^(2,N) ^(g) (N_(g)=2) are given by:

$W_{l,m,p,n}^{1,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{{\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}}\end{bmatrix}W_{l,m,p,n}^{2,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}}\end{bmatrix}{where}\mspace{14mu} {\begin{matrix}{p = \begin{bmatrix}p_{1} & p_{2}\end{bmatrix}} \\{n = \begin{bmatrix}n_{0} & n_{1} & n_{2}\end{bmatrix}}\end{matrix}.}}}}}}}$

The Mode2 codebooks for 1-4 layers are given respectively in TABLES50-53.

TABLE 50 Codebook for Mode2 1-layer CSI reporting using antenna ports[15 to 14 + P_(CSI-RS)] N_(g) = 2 i_(1,1) i_(1,2) i_(1,4,q), q = 1, 2i_(2,0) i_(2,1,q), q = 1, 2 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ −1 0, 1, 2, 3 0, 1, 2, 3 0, 1 W_(i) _(1,1), i_(1,2),i_(1,4), i₂ ⁽¹⁾ whereW_(l,m,p,n) ⁽¹⁾ = W_(l,m,p,n) ^(1,N) _(g).

TABLE 51 Codebook for Mode2 2-layer CSI reporting using antenna ports[15 to 14 + P_(CSI-RS)] N_(g) = 2 i_(1,1) i_(1,2) i_(1,4,q), q = 1, 2i_(2,0),i_(2,1,q), q = 1, 2 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ −1 0, 1, 2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i)_(1,2) ₊ _(k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽²⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {{\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g}} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g}}\end{bmatrix}}.}$

TABLE 52 Codebook for Mode2 3-layer CSI reporting using antenna ports[15 to 14 + P_(CSI-RS)] N_(g) = 2 i_(1,1) i_(1,2) i_(1,4,q), q = 1, 2i_(2,0),i_(2,3,q), q = 1, 2 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ −1 0, 1, 2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i)_(1,2) ₊ _(k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽³⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)}} = {{\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g}} & \begin{matrix}W_{l^{\prime},m^{\prime},p,n}^{1,N_{g}} & W_{l,m,p,n}^{2,N_{g}}\end{matrix}\end{bmatrix}}.}$

TABLE 53 Codebook for Mode2 4-layer CSI reporting using antenna ports[15 to 14 + P_(CSI-RS)] N_(g) = 2 i_(1,1) i_(1,2) i_(1,4,q), q = 1, 2i_(2,0),i_(2,1,q), q = 1, 2 0, 1, . . . , N₁O₁ − 1 0, 1, . . . , N₂O₂ −1 0, 1, 2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1) ₊ _(k) ₁ _(,i) _(1,2) _(,i)_(1,2) ₊ _(k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽⁴⁾${{{wher}e}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)}} = {{\frac{1}{\sqrt{4}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g}} & \begin{matrix}W_{l^{\prime},m^{\prime},p,n}^{1,N_{g}} & W_{l,m,p,n}^{2,N_{g}} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g}}\end{matrix}\end{bmatrix}}.}$

In one embodiment 14A, the 1-4 layer codebooks for Mode2 givenrespectively in TABLES 50-53 are also supported for N_(g)=4, wherei_(1,4) and i₂ are replaced with the following:

$i_{1,4} = \left\{ {{{\begin{matrix}\begin{bmatrix}i_{1,4,1} & i_{1,4,2}\end{bmatrix} & {N_{g} = 2} \\\begin{bmatrix}i_{1,4,1} & i_{1,4,2} & i_{1,4,3} & i_{1,4,4} & i_{1,4,5} & i_{1,4,6}\end{bmatrix} & {N_{g} = 4}\end{matrix}i_{1,4,q}} \in \left\{ {0,1,2,3} \right\}},{q = 1},\ldots \mspace{14mu},{{2\left( {N_{g} - 1} \right)};}} \right.$

and the quantities W_(l,m,p,n) ^(1,N) ^(g) and W_(l,m,p,n) ^(2,N) ^(g)for

$i_{2} = \left\{ {{{\begin{matrix}\begin{bmatrix}i_{2,0} & i_{2,1,1} & i_{2,1,2}\end{bmatrix} & {N_{g} = 2} \\\begin{bmatrix}i_{2,0} & i_{2,1,1} & i_{2,1,2} & i_{2,1,3} & i_{2,1,4} & i_{2,1,5} & i_{2,1,6}\end{bmatrix} & {N_{g} = 4}\end{matrix}i_{2,1,q}} \in \left\{ {0,1} \right\}},{q = 1},\ldots \mspace{14mu},{{2\left( {N_{g} - 1} \right)N_{g}} = {{4\mspace{14mu} {are}\mspace{14mu} {given}\mspace{14mu} {by}\text{:}\mspace{14mu} W_{l,m,p,n}^{2,1,4}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{{\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}}\end{bmatrix}W_{l,m,p,n}^{2,2,4}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{{- a_{p_{4}}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} \\{{- a_{p_{6}}}b_{n_{6}}v_{l,m}}\end{bmatrix}{where}\mspace{14mu} {\begin{matrix}{p = \begin{bmatrix}p_{1} & p_{2} & p_{3} & p_{4} & p_{5} & p_{6}\end{bmatrix}} \\{n = \begin{bmatrix}n_{0} & n_{1} & n_{2} & n_{3} & n_{4} & n_{5} & n_{6}\end{bmatrix}}\end{matrix}.}}}}}}}}}} \right.$

FIG. 13 illustrates an example multiple antenna panels with 2 ports perpanel 1300 according to embodiments of the present disclosure. Theembodiment of the multiple antenna panels with 2 ports per panelillustrated in FIG. 13 is for illustration only. FIG. 13 does not limitthe scope of this disclosure to any particular implementation.

The present disclosure provides the CSI acquisition scheme for theantenna structure to which multiple antenna panels are applied, whereeach panel is a dual-polarized antenna ports with N₁=1 and N₂=1 ports intwo dimensions, i.e., 2 ports per panel. As shown in FIG. 13, there areN_(g)=2, 4 antenna panels with 2 ports per panel.

In one embodiment Al, a UE is configured with the PMI codebook withpre-coder W for (N_(g), N₁, N₂) ∈ {(2,1,1),(4,1,1)} antenna panelsaccording to at least one of the following alternatives. In one exampleof Alt A1-0 (common intra-panel phase), W=c⊗d or d⊗c where c is anintra-panel phase vector (size 2×1), common for all panels, and d is aninter-panel phase vector (size N_(g)×1), where c⊗d denotes the Kroneckerproduct of c and d which is defined as c⊗d=[c₀d c₁d]^(T) where d=[d₀ d₁. . . d_(N) _(g) ⁻¹]. If W=c⊗d, for N_(g)=2, W=[c₀d₀ c₀d₁ c₁d₀c₁d₁]^(T). If one of c₀ and d₀ is fixed to 1, there may be one of thetwo alternate forms for W. In one instance, W=[d₀ d₁ c₁d₀ c₁d₁]^(T). Inone instance, W=[c₀ c₀d₁ c₁ c₁d₁]^(T). If both c₀ and d₀ are fixed to 1,then W=[1 d₁ c₁ c₁d₁]^(T).

If W=c ⊗d, f or N_(g)=4: W=[c₀d₀ c₀d₁ c₀d₂ c₀d₃ c₁d₀ c₁d₁ c₁d₂c₁d₃]^(T); since one of c₀ and d₀ can be fixed to 1, thers may be one ofthe two alternate forms for W. In one instance, W=[d₀ d₁ d₂ d₃ c₁d₀ c₁d₁c₁d₂ c₁d₃]^(T). In one instance, W=[c₀ c₀d₁ c₀d₂ c₀d₃ c₁ c₁d₁ c₁d₂c₁d₃]^(T). If both c₀ and d₀ are fixed to 1, then W=[1 d₁ d₂ d₃ c₁ c₁d₁c₁d₂ c₁d₃]^(T).

If W=d⊗c, then, for N_(g)=2: W=[c₀d₀ c₁d₀ c₀d₁ c₁d₁]^(T); since one ofc₀ and d₀ can be fixed to 1, there may be one of the two alternate formsfor W. In one instance, W=[d₀ c₁d₀ d₁ c₁d₁]^(T). In one instance, W=[c₀c₁ c₀d₁ c₁d₁]^(T). If W=d⊗c, then, for N_(g)=4: W=[c₀d₀ c₁d₀ c₀d₁ c₁d₁c₀d₂ c₁d₂ c₀d₃ c₁d₃]^(T); since one of c₀ and d₀ can be fixed to 1,there may be one of the two alternate forms for W. In one instance, =[d₀c₁d₀ d₁ c₁d₁ d₂ c₁d₂ d₃ c₁d₃]^(T). In one instance, W=[c₀ c₁ c₀d₁ c₁d₁c₀d₂ c₁d₂ c₀d₃ c₁d₃]^(T).

In one example of Alt A 1-1 (per panel phase): W=[1 c₁ c₂ c₃ . . .c_(2N) _(g) ⁻¹]^(T), where {c_(i)} are independent phase for N_(g)panels and 2 polarizations. For N_(g)=2: W=[1 c₁ c₂ c₃]^(T). ForN_(g)=4: W=[1 c₁ c₂ c₃ c4 c₅ c₆ c₇]^(T).

The codebook to report the pre-coder W is at least one of BPSK {1,−1} orQPSK {1,j,−1,−j} or two stage a_(WB)b_(WB) where a_(WB) and a_(SB)codebooks are according to at least one of the following:a_(WB)={1,j,−1, −j} (2 bit WB phase) and a_(SB)={1,j} (1-bit SB phase);a_(WB)={1,j,−1, −j} (2 bit WB phase) and a_(SB)={1, −j} (1-bit SBphase); a_(WB)={1,j, −1, −j} (2 bit WB phase) and

$a_{SB} = \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

(1-bit SB phase);

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\pi}{4}},e^{\frac{j\; 5\pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

(2 bit WB phase)and

$a_{SB} = \left\{ {e^{- \frac{j\; \pi}{4}},e^{\frac{j\; \pi}{4}}} \right\}$

(1-bit SB phase);

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\pi}{4}},e^{\frac{j\; 5\pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

(2 bit WB phase) and a_(SB)={1, −j} (1-bit SB phase); and

$a_{WB} = \left\{ {e^{\frac{j\; \pi}{4}},e^{\frac{j\; 3\pi}{4}},e^{\frac{j\; 5\pi}{4}},e^{\frac{j\; 7\pi}{4}}} \right\}$

(2 bit WB phase) and a_(SB)={1, j} (1-bit SB phase).

In one embodiment A2, the multi-panel codebook for (N_(g), N₁, N₂) ∈{(2,1,1),(4,1,1)} is based on a modular approach where the multi-panelpre-coder vector/matrix W_(MP) is built from the single-panel pre-codervector/matrix W_(SP) as follows. In one example of N_(g)=2:

${{{Rank}\mspace{14mu} 1\text{:}\mspace{14mu} W_{MP}} = {\begin{bmatrix}W_{SP} \\{e^{j\; \alpha_{1}}W_{SP}}\end{bmatrix} = {\begin{bmatrix}W \\{e^{j\; \alpha_{1}}W}\end{bmatrix} = \begin{bmatrix}1 \\e^{j\; \beta} \\e^{j\; \alpha_{1}} \\e^{j{({\alpha_{1} + \beta})}}\end{bmatrix}}}};{and}$${{Rank}\mspace{14mu} 2\text{:}\mspace{14mu} W_{MP}} = {\begin{bmatrix}W_{SP} \\{e^{j\; \alpha_{1}}W_{SP}}\end{bmatrix} = {\begin{bmatrix}W \\{e^{j\; \alpha_{1}}W}\end{bmatrix} = {\begin{bmatrix}1 & 1 \\e^{j\; \beta} & {- e^{j\; \beta}} \\e^{j\; \alpha_{1}} & e^{j\; \alpha_{1}} \\e^{j{({\alpha_{1} + \beta})}} & {- e^{j{({\alpha_{1} + \beta})}}}\end{bmatrix}.}}}$

In one example of N_(g)=4:

${{{Rank}\mspace{14mu} 1\text{:}\mspace{14mu} W_{MP}} = {\begin{bmatrix}W_{SP} \\{e^{j\; \alpha}W_{SP}}\end{bmatrix} = {\begin{bmatrix}W \\{e^{j\; \alpha_{1}}W} \\{e^{j\; \alpha_{2}}W} \\{e^{j\; \alpha_{3}}W}\end{bmatrix} = \begin{bmatrix}1 \\e^{j\; \beta} \\e^{j\; \alpha_{1}} \\e^{j{({\alpha_{1} + \beta})}} \\e^{j\; \alpha_{2}} \\e^{j{({\alpha_{2} + \beta})}} \\e^{j\; \alpha_{3}} \\e^{j{({\alpha_{3} + \beta})}}\end{bmatrix}}}};{and}$${{{Rank}\mspace{14mu} 2\text{:}\mspace{14mu} W_{MP}} = {\begin{bmatrix}W_{SP} \\{e^{j\; \alpha}W_{SP}}\end{bmatrix} = {\begin{bmatrix}W \\{e^{j\; \alpha_{1}}W} \\{e^{j\; \alpha_{2}}W} \\{e^{j\; \alpha_{3}}W}\end{bmatrix} = \begin{bmatrix}1 & 1 \\e^{j\; \beta} & {- e^{j\; \beta}} \\e^{j\; \alpha_{1}} & e^{j\; \alpha_{1}} \\e^{j{({\alpha_{1} + \beta})}} & {- e^{j{({\alpha_{1} + \beta})}}} \\e^{j\; \alpha_{2}} & e^{j\; \alpha_{2}} \\e^{j{({\alpha_{2} + \beta})}} & {- e^{j{({\alpha_{2} + \beta})}}} \\e^{j\; \alpha_{3}} & e^{j\; \alpha_{3}} \\e^{j{({\alpha_{3} + \beta})}} & {- e^{j{({\alpha_{3} + \beta})}}}\end{bmatrix}}}},$

where the selection of W_(SP) is limited to be the same for all panels;and the inter-panel phase e^(jα) ^(i) (i=1 or 1-3) can be reportedeither WB or SB or both WB and SB; and the co-phase e^(kβ) is reportedSB.

In one embodiment A3, a UE is configured with a PMI codebook for(N_(g),N₁, N₂) ∈ {(2,1,1),(4,1,1)} as follows. For 4 antenna ports (e.g.{3000, 3001 . . . , 3003), 8 antenna ports (e.g. {3000, 3001 . . . ,3007}), and the UE configured with higher layer parameters CodebookTypeset to Type1_MultiPanel and CodebookParameters set to Type1_Parameterswhich includes {NumberOfPanels, CodebookConfig-N1, CodebookConfig-N2,CodebookMode}. The values of N_(g), N₁, and N₂ are configured with thehigher-layer parameters NumberOfPanels, CodebookConfig-N1 andCodebookConfig-N2, respectively. The number of CSI-RS ports, P_(CSI-RS),is 2N_(g)N₁N₂ which equals 2N_(g) if (N₁,N₂)=(1,1). When N_(g)=2,CodebookMode may be set to either Config1 or Config2. When N_(g)=4,CodebookMode may be set to Config1.

Each PMI value corresponds to the codebook indices i₁ and i₂, where i₁is the vector given by:

$i_{1} = \left\{ \begin{matrix}\begin{bmatrix}i_{1,1} & i_{1,2} & i_{1,4}\end{bmatrix} & {\upsilon = 1} \\\begin{bmatrix}i_{1,1} & i_{1,2} & i_{1,3} & i_{1,4}\end{bmatrix} & {\upsilon \in \left\{ {2,3,4} \right\}}\end{matrix} \right.$

and v is the associated RI value. When CodebookMode is set to Config1,i_(1,4) is

$i_{1,4} = \left\{ {\begin{matrix}i_{1,4,1} & {N_{g} = 2} \\\begin{bmatrix}i_{1,4,1} & i_{1,4,2} & i_{1,4,3}\end{bmatrix} & {N_{g} = 4}\end{matrix}.} \right.$

When CodebookMode is set to Config2, i_(1,4)and i₂ are

$i_{1,4} = \begin{bmatrix}i_{1,4,1} & i_{1,4,2}\end{bmatrix}$ $i_{2} = {\begin{bmatrix}i_{2,0} & i_{2,1} & i_{2,2}\end{bmatrix}.}$

A UE may only use i_(1,2)=0 and may not report i_(1,2) if the value ofCodebookConfig-N1 is set to greater than 1 and CodebookConfig-N2 is setto 1. A UE may only use i_(1,1)=i_(1,2)=i_(1,3)=0 and may not reporti_(1,1), i_(1,2), and i_(1,3) if the value of CodebookConfig-N1 andCodebookConfig-N2 are set to 1.

The quantities φ_(n), a_(p), b_(n), u_(m), and v_(l,m) are given by

ϕ_(n) = e^(j π n/2) a_(p) = e^(j π/4)e^(j π p/2)b_(n) = e^(−j π /4)e^(j π n/2) $u_{m} = \left\{ {{\begin{matrix}\begin{bmatrix}1 & e^{j\frac{2\; \pi \; m}{O_{2}N_{2}}} & \ldots & e^{j\frac{2\; \pi \; {m{({N_{2} - 1})}}}{O_{2}N_{2}}}\end{bmatrix} & {N_{2} > 1} \\1 & {N_{2} = 1}\end{matrix}v_{l,m}} = \left\{ {\begin{matrix}\left\lbrack {\begin{matrix}u_{m} & {e^{j\frac{2\; \pi \; l}{O_{1}N_{1}}}u_{m}} & \ldots & e^{j\frac{2\; \pi \; {l{({N_{1} - 1})}}}{O_{1}N_{1}}}\end{matrix}u_{m}} \right\rbrack^{T} & {N_{2} > 1} \\1 & {\mspace{14mu} \begin{matrix}{N_{1} = {N_{2} = {1\mspace{14mu} {or}}}} \\{l = {m = 0}}\end{matrix}}\end{matrix}.} \right.} \right.$

Furthermore, the quantities W_(l,m,p,n) ^(1,N) ^(g) ^(,1), W_(l,m,p,n)^(2,N) ^(g) ^(,1), W_(l,m,p,n) ^(3,N) ^(g) ^(,1), and W_(l,m,p,n) ^(4,N)^(g) ^(,1) (

$W_{l,m,p,n}^{1,2,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{{\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}}\end{bmatrix}W_{l,m,p,n}^{2,2,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}}\end{bmatrix}}}}}}$

N_(g) ∈ [2,4]) are given by:

$W_{l,m,p,n}^{3,2,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{{\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{{- \phi_{p_{1}}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}}\end{bmatrix}W_{l,m,p,n}^{4,2,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{{\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{{- \phi_{p_{1}}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}}\end{bmatrix}W_{l,m,p,n}^{1,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{{\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix}W_{l,m,p,n}^{2,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{{\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix}W_{l,m,p,n}^{3,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{{\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{{- \phi_{p_{1}}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{{- \phi_{p_{3}}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix}W_{l,m,p,n}^{4,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{{\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{{- \phi_{p_{1}}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{{- \phi_{p_{3}}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix}{where}\mspace{14mu} p} = \left\{ {\begin{matrix}p_{1} & {N_{g} = 2} \\\begin{bmatrix}p_{1} & p_{2} & p_{3}\end{bmatrix} & {N_{g} = 4}\end{matrix},} \right.}}}}}}}}}}}}}}}}}}$

and thequantities W_(l,m,p,n) ^(1,N) ^(g) ^(,2), W_(l,m,p,n) ^(2,N) ^(g) ^(,2),W_(l,m,p,n) ^(3,N) ^(g) ^(,2), and W_(l,m,p,n) ^(4,N) ^(g) ^(,2)(N_(g)=2) are given by:

$W_{l,m,p,n}^{1,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{p_{2}}v_{l,m}}\end{bmatrix}}$${W_{l,m,p,n}^{2,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{p_{2}}v_{l,m}}\end{bmatrix}}}\mspace{11mu}$${W_{l,m,p,n}^{3,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{{- a_{p_{1}}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{p_{2}}v_{l,m}}\end{bmatrix}}}\mspace{11mu}$$\; {W_{l,m,p,n}^{4,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{{- a_{p_{1}}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{p_{2}}v_{l,m}}\end{bmatrix}}}\mspace{11mu}$ where $p = {{\begin{bmatrix}p_{1} & p_{2}\end{bmatrix}n} = {\begin{bmatrix}n_{0} & n_{1} & n_{2}\end{bmatrix}.}}$

The codebooks for 1-4 layers are given respectively in TABLES 54-57,where (k₁,k₂)=(0,0) if (N₁, N₂)=(1, 1).

TABLE 54 Codebook for 1-layer CSI reporting using antenna ports [3000 to2999 + P_(CSI-RS)] Config1, (N_(g), N₁, N₂) ∈ {(2, 1, 1), (4, 1, 1)}i_(1, 1) i_(1, 2) i_(1, 4, q), q = 1, . . . , N_(g) − 1 i₂ 0 0 0, 1, 2,3 0, 1, 2, 3 W_(i) _(1, 1) _(, i) _(1, 2) _(, i) _(1, 4) _(, i) ₂ ⁽¹⁾where W_(l, m, p, n) ⁽¹⁾ = W_(l, m, p, n) ^(1, N) ^(g) ^(, 1). Config2,(N_(g), N₁, N₂) = (2, 1, 1) i_(1, 1) i_(1, 2) i_(1, 4, q), q = 1, 2i_(2, 0) i_(2, q), q = 1, 2 0 0 0, 1, 2, 3 0, 1, 2, 3 0, 1 W_(i) _(1, 1)_(, i) _(1, 2) _(, i) _(1, 4) _(, i) ₂ ⁽¹⁾ where W_(l, m, p, n) ⁽¹⁾ =W_(l, m, p, n) ^(1, N) ^(g) ^(, 2).

TABLE 55 Codebook for 2-layer CSI reporting using antenna ports [3000 to2999 + P_(CSI-RS)] Config1, (N_(g), N₁, N₂) ∈ {(2, 1, 1), (4, 1, 1)}i_(1,1) i_(1,2) i_(1,4,q), q = 1, . . . , N_(g) − 1 i₂ 0 0 0, 1, 2, 3 0,1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,i) ₂ ⁽²⁾${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {{\frac{1}{\sqrt{2}}\left\lbrack {W_{l,m,p,n}^{1,N_{g},1}\mspace{31mu} W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1}} \right\rbrack}.}$Config2, (N_(g), N₁, N₂) = (2, 1, 1) i_(1,1) i_(1,2) i_(1,4,q), q = 1, 2i_(2,q), q = 0, 1, 2 0 0 0, 1, 2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1) _(+k)₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽²⁾${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)}} = {{\frac{1}{\sqrt{2}}\left\lbrack {W_{l,m,p,n}^{1,N_{g},2}\mspace{31mu} W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2}} \right\rbrack}.}$

TABLE 56 Codebook for 3-layer CSI reporting using antenna ports [3000 to2999+_(CSI-RS)] Config1, (N_(g), N₁, N₂) ∈ {(2, 1, 1), (4, 1, 1)}i_(1,1) i_(1,2) i_(1,4,q), q = 1, . . . , N_(g) − 1 i₂ 0 0 0, 1, 2, 3 0,1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,i) ₂ ⁽³⁾${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)}} = {{\frac{1}{\sqrt{3}}\left\lbrack {W_{l,m,p,n}^{1,N_{g},1}\mspace{31mu} W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1}\mspace{31mu} W_{l,m,p,n}^{3,N_{g},1}} \right\rbrack}.}$Config2, (N_(g), N₁, N₂) = (2, 1, 1) i_(1,1) i_(1,2) i_(1,4,q), q = 1, 2i_(2,q), q = 0, 1, 2 0 0 0, 1, 2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1) _(+k)₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽³⁾${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)}} = {{\frac{1}{\sqrt{3}}\left\lbrack {W_{l,m,p,n}^{1,N_{g},2}\mspace{31mu} W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2}\mspace{31mu} W_{l,m,p,n}^{3,N_{g},2}} \right\rbrack}.}$

TABLE 57 Codebook for 4-layer CSI reporting using antenna ports [3000 to2999 + P_(CSI-RS)] Config1, (N_(g), N₁, N₂) ∈ {(2, 1, 1), (4, 1, 1)}i_(1,1) i_(1,2) i_(1,4,q), q = 1, . . . , N_(g) − 1 i₂ 0 0 0, 1, 2, 3 0,1 W_(i) _(1,1) _(,i) _(1,1) _(+k) ₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂_(,i) _(1,4) _(,i) ₂ ⁽⁴⁾${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)}} = {{\frac{1}{\sqrt{4}}\left\lbrack {W_{l,m,p,n}^{1,N_{g},1}\mspace{31mu} W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1}\mspace{31mu} W_{l,m,p,n}^{3,N_{g},1}\mspace{31mu} W_{l^{\prime},m^{\prime},p,n}^{4,N_{g},1}} \right\rbrack}.}$Config2, (N_(g), N₁, N₂) = (2, 1, 1) i_(1,1) i_(1,2) i_(1,4,q), q = 1, 2i_(2,q), q = 0, 1, 2 0 0 0, 1, 2, 3 0, 1 W_(i) _(1,1) _(,i) _(1,1) _(+k)₁ _(,i) _(1,2) _(,i) _(1,2) _(+k) ₂ _(,i) _(1,4) _(,i) ₂ ⁽⁴⁾${{where}\mspace{14mu} W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)}} = {{\frac{1}{\sqrt{4}}\left\lbrack {W_{l,m,p,n}^{1,N_{g},2}\mspace{31mu} W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2}\mspace{31mu} W_{l,m,p,n}^{3,N_{g},2}\mspace{31mu} W_{l^{\prime},m^{\prime},p,n}^{4,N_{g},2}} \right\rbrack}.}$

In one embodiment A3A, the 1-4 layer codebooks for Config2 givenrespectively in TABLES 54-57 are also supported for N_(g)=4, wherei_(1,4) and i₂ are replaced with the following:

$i_{1,4} = \left\{ {{{\begin{matrix}\begin{bmatrix}i_{1,4,1} & i_{1,4,2}\end{bmatrix} & {N_{g} = 2} \\\begin{bmatrix}i_{1,4,1} & i_{1,4,2} & i_{1,4,3} & i_{1,4,4} & i_{1,4,5} & i_{1,4,6}\end{bmatrix} & {N_{g} = 4}\end{matrix}i_{1,4,q}} \in \left\{ {0,1,2,3} \right\}},{q = 1},\ldots \mspace{14mu},{{2\mspace{14mu} \left( {N_{g} - 1} \right)i_{2}} = \left\{ {\begin{matrix}\begin{bmatrix}i_{2,0} & i_{2,1} & i_{2,2}\end{bmatrix} & {N_{g} = 2} \\\begin{bmatrix}i_{2,0} & i_{2,1} & i_{2,2} & i_{2,3} & i_{2,4} & i_{2,5} & i_{2,6}\end{bmatrix} & {N_{g} = 4}\end{matrix};} \right.}} \right.$

and the quantities W_(l,m,p,n) ^(1,N) ^(g) ^(,2), W_(l,m,p,n) ^(2,N)^(g) ^(,2),

i _(2,q) ∈ {0,1},q=1, . . . , 2 (N_(g)−1)

i _(2,0) ∈ {0,1,2,3} v=1

i _(2,0) ∈ {0,1} v=2,3,4

W_(l,m,p,n) ^(3,N) ^(g) ^(,2) and W_(l,m,p,n) ^(4,N) ^(g) ^(,2) forN_(g)=4 are given by:

$W_{l,m,p,n}^{1,4,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{2,4,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{{- a_{p_{4}}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} \\{{- a_{p_{6}}}b_{n_{6}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{3,4,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{{- a_{p_{1}}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} \\{{- a_{p_{5}}}b_{n_{5}}v_{l,m}} \\{{- a_{p_{6}}}b_{n_{6}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{4,4,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{{- a_{p_{1}}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{{- a_{p_{4}}}b_{n_{4}}v_{l,m}} \\{{- a_{p_{5}}}b_{n_{5}}v_{l,m}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}}\end{bmatrix}}$ where $p = \begin{bmatrix}p_{1} & p_{2} & p_{3} & p_{4} & p_{5} & p_{6}\end{bmatrix}$ $n = {\begin{bmatrix}n_{0} & n_{1} & n_{2} & n_{3} & n_{4} & n_{5} & n_{6}\end{bmatrix}.}$

In one embodiment A3B, the pre-coding matrix expression in the 3 layercodebook TABLE 56 is replaced with one of following:

$W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1} & W_{l,m,p,n}^{4,N_{g},1}\end{bmatrix}}$

for Config1 and

$W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2} & W_{l,m,p,n}^{4,N_{g},2}\end{bmatrix}}$

for Config2;

$W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{3,N_{g},1} & W_{l,m,p,n}^{4,N_{g},1}\end{bmatrix}}$

for Config1 and

$W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{3,N_{g},2} & W_{l,m,p,n}^{4,N_{g},2}\end{bmatrix}}$

for Config2; and

$W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{2,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{3,N_{g},1} & W_{l,m,p,n}^{4,N_{g},1}\end{bmatrix}}$

for Config1 and

$W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{2,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{3,N_{g},2} & W_{l,m,p,n}^{4,N_{g},2}\end{bmatrix}}$

for Config2.

In one embodiment A3C, the quantities W_(l,m,p,n) ^(1,N) ^(g) ^(,1),W_(l,m,p,n) ^(2,N) ^(g) ^(,1), W_(l,m,p,n) ^(3,N) ^(g) ^(,1) andW_(l,m,p,n) ^(4,N) ^(g) ^(,1) for N_(g)=4 in TABLES 54-57 are given by:

$W_{l,m,p,n}^{1,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{2,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{{- \phi_{p_{1}}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{{- \phi_{p_{3}}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{3,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{{- \phi_{p_{2}}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{{- \phi_{p_{3}}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{4,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{{- \phi_{p_{1}}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{{- \phi_{p_{2}}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}$

and the quantities W_(l,m,p,n) ^(1,N) ^(g) ^(,2), W_(l,m,p,n) ^(2,N)^(g) ^(,2), W_(l,m,p,n) ^(3,N) ^(g) ^(,2)and W_(l,m,p,n) ^(4,N) ^(g)^(,2) for N_(g)=4 are given by:

$W_{l,m,p,n}^{1,4,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{2,4,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{{- a_{p_{1}}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} \\{{- a_{p_{5}}}b_{n_{5}}v_{l,m}} \\{{- a_{p_{6}}}b_{n_{6}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{3,4,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{{- a_{p_{3}}}b_{n_{3}}v_{l,m}} \\{{- a_{p_{4}}}b_{n_{4}}v_{l,m}} \\{{- a_{p_{5}}}b_{n_{5}}v_{l,m}} \\{{- a_{p_{6}}}b_{n_{6}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{4,4,2} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{{- a_{p_{1}}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}} \\{{- a_{p_{3}}}b_{n_{3}}v_{l,m}} \\{{- a_{p_{4}}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}}\end{bmatrix}}.}$

In one embodiment A3D, the quantities W_(l,m,p,n) ^(1,N) ^(g) ^(,1),W_(l,m,p,n) ^(2,N) ^(g) ^(,1), W_(l,m,p,n) ^(3,N) ^(g) ^(,1) andW_(l,m,p,n) ^(4,N) ^(g) ^(,1) for N_(g)=4 in TABLES 54-57 are given by:

$W_{l,m,p,n}^{1,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{2,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{{- \phi_{p_{1}}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{{- \phi_{p_{3}}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{3,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{{- \phi_{p_{2}}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{{- \phi_{p_{3}}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{4,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{{- \phi_{p_{1}}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{{- \phi_{p_{2}}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}$

and the quantities W_(l,m,p,n) ^(1,N) ^(g) ^(,2), W_(l,m,p,n) ^(2,N)^(g) ^(,2). W_(l,m,p,n) ^(3,N) ^(g) ^(,2) and W_(l,m,p,n) ^(4,N) ^(g)^(,2) for N_(g)=4 are given by:

$W_{l,m,p,n}^{1,4,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{{- a_{p_{4}}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} \\{{- a_{p_{6}}}b_{n_{6}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{2,4,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{{- a_{p_{1}}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{a_{p_{3}}b_{n_{3}}v_{l,m}} \\{{- a_{p_{4}}}b_{n_{4}}v_{l,m}} \\{{- a_{p_{5}}}b_{n_{5}}v_{l,m}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{3,4,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}} \\{{- a_{p_{3}}}b_{n_{3}}v_{l,m}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} \\{{- a_{p_{5}}}b_{n_{5}}v_{l,m}} \\{a_{p_{6}}b_{n_{6}}v_{l,m}}\end{bmatrix}}$$W_{l,m,p,n}^{4,4,2} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{{- a_{p_{1}}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}} \\{{- a_{p_{3}}}b_{n_{3}}v_{l,m}} \\{a_{p_{4}}b_{n_{4}}v_{l,m}} \\{a_{p_{5}}b_{n_{5}}v_{l,m}} \\{{- a_{p_{6}}}b_{n_{6}}v_{l,m}}\end{bmatrix}}.}$

In one embodiment A4, the codebook table for (N_(g), N₁, N₂) ∈{(2,1,1),(4,1,1)} is as shown in TABLES 58-61, respectively, for 1-4layer CSI reporting, where the PMI indices i_(1,4) and i₂ are defined asin embodiment A3, and where the quantities W_(p,n) ^(1,N) ^(g) ^(,1),W_(p,n) ^(2,N) ^(g) ^(,1), W_(p,n) ^(3,N) ^(g) ^(,1), and W_(p,n) ^(4,N)^(g) ^(,1) (N_(g) ∈ {2,4}) are given by:

$W_{p,n}^{1,2,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\\phi_{p_{1}} \\{\phi_{n}\phi_{p_{1}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,2,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\\phi_{p_{1}} \\{{- \phi_{n}}\phi_{p_{1}}}\end{bmatrix}}}$$W_{p,n}^{3,2,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\{- \phi_{p_{1}}} \\{{- \phi_{n}}\phi_{p_{1}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,2,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\{- \phi_{p_{1}}} \\{\phi_{n}\phi_{p_{1}}}\end{bmatrix}}}$$W_{p,n}^{1,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\\phi_{p_{1}} \\{\phi_{n}\phi_{p_{1}}} \\\phi_{p_{2}} \\{\phi_{n}\phi_{p_{2}}} \\\phi_{p_{3}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\\phi_{p_{1}} \\{{- \phi_{n}}\phi_{p_{1}}} \\\phi_{p_{2}} \\{{- \phi_{n}}\phi_{p_{2}}} \\\phi_{p_{3}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}}$$W_{p,n}^{3,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\{- \phi_{p_{1}}} \\{{- \phi_{n}}\phi_{p_{1}}} \\\phi_{p_{2}} \\{\phi_{n}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\{- \phi_{p_{1}}} \\{\phi_{n}\phi_{p_{1}}} \\\phi_{p_{2}} \\{{- \phi_{n}}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}}$ ${{where}\mspace{14mu} p} = \left\{ {\begin{matrix}p_{1} & {N_{g} = 2} \\\begin{bmatrix}p_{1} & p_{2} & p_{3}\end{bmatrix} & {N_{g} = 4}\end{matrix},} \right.$

and the quantities W_(p,n) ^(1,N) ^(g) ^(,2), W_(p,n) ^(2,N) ^(g) ^(,2),W_(p,n) ^(3,N) ^(g) ^(,2), and W_(p,n) ^(4,N) ^(g) ^(,2) (N_(g)2) aregiven by:

$W_{p,n}^{1,2,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{a_{p_{1}}b_{n_{1}}} \\{a_{p_{2}}b_{p_{2}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,2,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{a_{p_{1}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{p_{2}}}\end{bmatrix}}}$$W_{p,n}^{3,2,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{p_{2}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,2,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{a_{p_{2}}b_{p_{2}}}\end{bmatrix}}}$ where $p = \begin{bmatrix}p_{1} & p_{2}\end{bmatrix}$ $n = {\begin{bmatrix}n_{0} & n_{1} & n_{2}\end{bmatrix}.}$

TABLE 58 Codebook for 1-layer CSI reporting using antenna ports [3000 to2999 + P_(CSI-RS)] Config1, (N_(g), N₁, N₂) ∈ {(2, 1, 1), (4, 1, 1)}i_(1, 4, q), q = 1, . . . , N_(g) − 1 i₂ 0, 1, 2, 3 0, 1, 2, 3 W_(i)_(1, 4) _(, i) ₂ ⁽¹⁾ where W_(p, n) ⁽¹⁾ = W_(p, n) ^(1, N) ^(g) ^(, 1).Config2, (N_(g), N₁, N₂) = (2, 1, 1) i_(1, 4, q), q = 1, 2 i_(2, 0)i_(2, q), q = 1, 2 0, 1, 2, 3 0, 1, 2, 3 0, 1 W_(i) _(1, 4) _(, i) ₂ ⁽¹⁾where W_(p, n) ⁽¹⁾ = W_(p, n) ^(1, N) ^(g) ^(, 2).

TABLE 59 Codebook for 2-layer CSI reporting using antenna ports [3000 to2999 + P_(CSI-RS)] Config1, (N_(g), N₁, N₂) ∈ {(2, 1, 1), (4, 1, 1)}i_(1,4,q), q = 1, . . . , N_(g) − 1 i₂ 0, 1, 2, 3 0, 1 W_(i) _(1,4)_(,i) ₂ ⁽²⁾${{where}\mspace{14mu} W_{p,n}^{(2)}} = {{\frac{1}{\sqrt{2}}\left\lbrack {W_{p,n}^{1,N_{g},1}\mspace{31mu} W_{p,n}^{2,N_{g},1}} \right\rbrack}.}$Config2, (N_(g), N₁, N₂) = (2, 1, 1) i_(1,4,q), q = 1, 2 i_(2,q), q = 0,1, 2 0, 1, 2, 3 0, 1 W_(i) _(1,4) _(,i) ₂ ⁽²⁾${{where}\mspace{14mu} W_{p,n}^{(2)}} = {{\frac{1}{\sqrt{2}}\left\lbrack {W_{p,n}^{1,N_{g},2}\mspace{31mu} W_{p,n}^{2,N_{g},2}} \right\rbrack}.}$

TABLE 60 Codebook for 3-layer CSI reporting using antenna ports [3000 to2999+_(CSI-RS)] Config1, (N_(g), N₁, N₂) ∈ {(2, 1, 1), (4, 1, 1)}i_(1,4,q), q = 1, . . . , N_(g) − 1 i₂ 0, 1, 2, 3 0, 1 W_(i) _(1,4)_(,i) ₂ ⁽³⁾${{where}\mspace{14mu} W_{p,n}^{(3)}} = {{\frac{1}{\sqrt{3}}\left\lbrack {W_{p,n}^{1,N_{g},1}\mspace{31mu} W_{p,n}^{2,N_{g},1}\mspace{31mu} W_{p,n}^{3,N_{g},1}} \right\rbrack}.}$Config2, (N_(g), N₁, N₂) = (2, 1, 1) i_(1,4,q), q = 1, 2 i_(2,q), q = 0,1, 2 0, 1, 2, 3 0, 1 W_(i) _(1,4) _(,i) ₂ ⁽³⁾${{where}\mspace{14mu} W_{p,n}^{(3)}} = {{\frac{1}{\sqrt{3}}\left\lbrack {W_{p,n}^{1,N_{g},2}\mspace{31mu} W_{p,n}^{2,N_{g},2}\mspace{31mu} W_{p,n}^{3,N_{g},2}} \right\rbrack}.}$

TABLE 61 Codebook for 4-layer CSI reporting using antenna ports [3000 to2999 + P_(CSI-RS)] Config1, (N_(g), N₁, N₂) ∈ {(2, 1, 1), (4, 1, 1)}i_(1,4,q), q = 1, . . . , N_(g) − 1 i₂ 0, 1, 2, 3 0, 1 W_(i) _(1,4)_(,i) ₂ ⁽⁴⁾${{where}\mspace{14mu} W_{p,n}^{(4)}} = {{\frac{1}{\sqrt{4}}\left\lbrack {W_{p,n}^{1,N_{g},1}\mspace{31mu} W_{p,n}^{2,N_{g},1}\mspace{31mu} W_{p,n}^{3,N_{g},1}\mspace{31mu} W_{p,n}^{4,N_{g},1}} \right\rbrack}.}$Config2, (N_(g), N₁, N₂) = (2, 1, 1) i_(1,4,q), q = 1, 2 i_(2,q), q = 0,1, 2 0, 1, 2, 3 0, 1 W_(i) _(1,4) _(,i) ₂ ⁽⁴⁾${{where}\mspace{14mu} W_{p,n}^{(4)}} = {{\frac{1}{\sqrt{4}}\left\lbrack {W_{p,n}^{1,N_{g},2}\mspace{31mu} W_{p,n}^{2,N_{g},2}\mspace{31mu} W_{p,n}^{3,N_{g},2}\mspace{31mu} W_{p,n}^{4,N_{g},2}} \right\rbrack}.}$

In one embodiment A4A, the 1-4 layer codebooks for Config2 givenrespectively in TABLES 58-61 are also supported for N_(g)=4, wherei_(1,4) and i₂ are replaced with the following:

$i_{1,4} = \left\{ {{{\begin{matrix}\begin{bmatrix}i_{1,4,1} & i_{1,4,2}\end{bmatrix} & {N_{g} = 2} \\\begin{bmatrix}i_{1,4,1} & i_{1,4,2} & i_{1,4,3} & i_{1,4,4} & i_{1,4,5} & i_{1,4,6}\end{bmatrix} & {N_{g} = 4}\end{matrix}i_{1,4,q}} \in \left\{ {0,1,2,3} \right\}},{q = 1},\ldots \mspace{14mu},{{2\mspace{14mu} \left( {N_{g} - 1} \right)i_{2}} = \left\{ {{\begin{matrix}\begin{bmatrix}i_{2,0} & i_{2,1} & i_{2,2}\end{bmatrix} & {N_{g} = 2} \\\begin{bmatrix}i_{2,0} & i_{2,1} & i_{2,2} & i_{2,3} & i_{2,4} & i_{2,5} & i_{2,6}\end{bmatrix} & {N_{g} = 4}\end{matrix};{i_{2,q} \in \left\{ {0,1} \right\}}},{q = 1},\ldots \mspace{14mu},{{{2\mspace{14mu} \left( {N_{g} - 1} \right)i_{2,0}} \in {\left\{ {0,1,2,3} \right\} \mspace{14mu} \upsilon}} = {{{1i_{2,0}} \in {\left\{ {0,1} \right\} \mspace{14mu} \upsilon}} = 2}},3,4} \right.}} \right.$

and the quantities W_(p,n) ^(1,N) ^(g) ^(,2), W_(p,n) ^(2,N) ^(g) ^(,2),W_(p,n) ^(3,N) ^(g) ^(,2) and

$W_{p,n}^{1,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{a_{p_{1}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{a_{p_{1}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}}$$W_{p,n}^{3,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}}$ where $p = \begin{bmatrix}p_{1} & p_{2} & p_{3} & p_{4} & p_{5} & p_{6}\end{bmatrix}$ $n = {\begin{bmatrix}n_{0} & n_{1} & n_{2} & n_{3} & n_{4} & n_{5} & n_{6}\end{bmatrix}.}$

In one embodiment A4B, the pre-coding matrix expression in the 3 layercodebook 60 is replaced with one of following:

$W_{p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{p,n}^{1,N_{g},1} & W_{p,n}^{2,N_{g},1} & W_{p,n}^{4,N_{g},1}\end{bmatrix}}$

for Config1 and

$W_{p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{p,n}^{1,N_{g},2} & W_{p,n}^{2,N_{g},2} & W_{p,n}^{4,N_{g},2}\end{bmatrix}}$

for Config2;

$W_{p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{p,n}^{1,N_{g},1} & W_{p,n}^{3,N_{g},1} & W_{p,n}^{4,N_{g},1}\end{bmatrix}}$

for Config1; and

$W_{p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{p,n}^{1,N_{g},2} & W_{p,n}^{3,N_{g},2} & W_{p,n}^{4,N_{g},2}\end{bmatrix}}$

for Config2; and

$W_{p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{p,n}^{2,N_{g},1} & W_{p,n}^{3,N_{g},1} & W_{p,n}^{4,N_{g},1}\end{bmatrix}}$

for Config1

and

$W_{p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{p,n}^{2,N_{g},2} & W_{p,n}^{3,N_{g},2} & W_{p,n}^{4,N_{g},2}\end{bmatrix}}$

for Config2

In one embodiment A4C, the quantities W_(p,n) ^(1,N) ^(g) ^(,1), W_(p,n)^(2,N) ^(g) ^(,1), W_(p,n) ^(3,N) ^(g) ^(,1) and W_(p,n) ^(4,N) ^(g)^(,1) for N_(g)=4 in TABLE 58-61 are given by:

$W_{p,n}^{1,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\\phi_{p_{1}} \\{\phi_{n}\phi_{p_{1}}} \\\phi_{p_{2}} \\{\phi_{n}\phi_{p_{2}}} \\\phi_{p_{3}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\{- \phi_{p_{1}}} \\{{- \phi_{n}}\phi_{p_{1}}} \\\phi_{p_{2}} \\{\phi_{n}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}}$$W_{p,n}^{3,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\\phi_{p_{1}} \\{\phi_{n}\phi_{p_{1}}} \\{- \phi_{p_{2}}} \\{{- \phi_{n}}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\{- \phi_{p_{1}}} \\{{- \phi_{n}}\phi_{p_{1}}} \\{- \phi_{p_{2}}} \\{{- \phi_{n}}\phi_{p_{2}}} \\\phi_{p_{3}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}}$

and the quantities W_(p,n) ^(1,N) ^(g) ^(,2), W_(p,n) ^(2,N) ^(g) ^(,2),W_(p,n) ^(3,N) ^(g) ^(,2) and W_(p,n) ^(4,N) ^(g) ^(,2) for N_(g)−4 aregiven by:

$W_{p,n}^{1,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{a_{p_{1}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}}$$W_{p,n}^{3,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{a_{p_{1}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{{- a_{p_{3}}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,2}} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{{- a_{p_{3}}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}.}}$

In one embodiment A4D, the quantities W_(p,n) ^(1,N) ^(g) ^(,1), W_(p,n)^(2,N) ^(g) ^(,1), W_(p,n) ^(3,N) ^(g) ^(,1) and W_(p,n) ^(4,N) ^(g)^(,1) for N_(g)=4 in TABLES 58-61 are given by:

$W_{p,n}^{1,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\\phi_{p_{1}} \\{{- \phi_{n}}\phi_{p_{1}}} \\\phi_{p_{2}} \\{{- \phi_{n}}\phi_{p_{2}}} \\\phi_{p_{3}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\{- \phi_{p_{1}}} \\{\phi_{n}\phi_{p_{1}}} \\\phi_{p_{2}} \\{{- \phi_{n}}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}}$$W_{p,n}^{3,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\\phi_{p_{1}} \\{{- \phi_{n}}\phi_{p_{1}}} \\{- \phi_{p_{2}}} \\{\phi_{n}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\{- \phi_{p_{1}}} \\{\phi_{n}\phi_{p_{1}}} \\{- \phi_{p_{2}}} \\{\phi_{n}\phi_{p_{2}}} \\\phi_{p_{3}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}}$

and the quantities W_(p,n) ^(1,N) ^(g) ^(,2), W_(p,n) ^(2,N) ^(g) ^(,2),W_(p,n) ^(3,N) ^(g) ^(,2) and W_(p,n) ^(4,N) ^(g) ^(,2) for N_(g)=4 aregiven by:

$W_{p,n}^{1,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{a_{p_{1}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}}$$W_{p,n}^{3,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{a_{p_{1}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{{- a_{p_{3}}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,2}} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{{- a_{p_{3}}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}.}}$

In one embodiment A5, the PMI codebook for rank 5, rank 6, rank 7, andrank 8 CSI reporting for (N_(g),N₁,N₂)=(4,1,1) are as shown in TABLES62-65, respectively where the quantities W_(p,n,) ^(1,N) ^(g) ^(,1),W_(p,n) ^(2,N) ^(g) ^(,1), W_(p,n) ^(3,N) ^(g) ^(,1), and W_(p,n) ^(4,N)^(g) ^(,1) are given by:

$W_{p,n}^{1,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\\phi_{p_{1}} \\{\phi_{n}\phi_{p_{1}}} \\\phi_{p_{2}} \\{\phi_{n}\phi_{p_{2}}} \\\phi_{p_{3}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\\phi_{p_{1}} \\{{- \phi_{n}}\phi_{p_{1}}} \\\phi_{p_{2}} \\{{- \phi_{n}}\phi_{p_{2}}} \\\phi_{p_{3}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}}$$W_{p,n}^{5,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\\phi_{p_{1}} \\{\phi_{n}\phi_{p_{1}}} \\{- \phi_{p_{2}}} \\{{- \phi_{n}}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{6,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\\phi_{p_{1}} \\{{- \phi_{n}}\phi_{p_{1}}} \\{- \phi_{p_{2}}} \\{\phi_{n}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}}$$W_{p,n}^{3,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\{- \phi_{p_{1}}} \\{{- \phi_{n}}\phi_{p_{1}}} \\\phi_{p_{2}} \\{\phi_{n}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\{- \phi_{p_{1}}} \\{\phi_{n}\phi_{p_{1}}} \\\phi_{p_{2}} \\{{- \phi_{n}}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}}$$W_{p,n}^{7,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\{- \phi_{p_{1}}} \\{{- \phi_{n}}\phi_{p_{1}}} \\{- \phi_{p_{2}}} \\{{- \phi_{n}}\phi_{p_{2}}} \\\phi_{p_{3}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{8,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\{- \phi_{p_{1}}} \\{\phi_{n}\phi_{p_{1}}} \\{- \phi_{p_{2}}} \\{\phi_{n}\phi_{p_{2}}} \\\phi_{p_{3}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}}$

the quantities W_(p,n) ^(1,N) ^(g) ^(,2), W_(p,n) ^(2,N) ^(g) ^(,2),W_(p,n) ^(3,N) ^(g) ^(,2), and W_(p,n) ^(4,N) ^(g) ^(,2) are giving by:

$W_{p,n}^{1,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{a_{p_{1}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{a_{p_{1}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}}$$W_{p,n}^{3,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}}$$W_{p,n}^{5,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{a_{p_{1}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{{- a_{p_{3}}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{6,4,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{a_{p_{1}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{{- a_{p_{3}}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}}$$W_{p,n}^{7,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{{- a_{p_{3}}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{8,4,2}} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{{- a_{p_{3}}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}.}}$

TABLE 62 Codebook for 5-layer CSI reporting using antenna ports [3000 to2999 + P_(CSI-RS)] Config1, (N_(g), N₁, N₂) = (4, 1, 1) i_(1,4,q), q =1, 2, 3 i₂ 0, 1, 2, 3 0, 1 W_(i) _(1,4) _(,i) ₂ ⁽⁵⁾${{where}\mspace{14mu} W_{p,n}^{(5)}} = {{\frac{1}{\sqrt{5}}\left\lbrack {W_{p,n}^{1,N_{g},1}\mspace{31mu} W_{p,n}^{2,N_{g},1}\mspace{31mu} W_{p,n}^{3,N_{g},1}\mspace{31mu} W_{p,n}^{4,N_{g},1}\mspace{31mu} W_{p,n}^{5,N_{g},1}} \right\rbrack}.}$Config2, (N_(g), N₁, N₂) = (4, 1, 1) i_(1,4,q), q = 1, . . . , 6i_(2,q), q = 0, 1, . . . , 6 0, 1, 2, 3 0, 1 W_(i) _(1,4) _(,i) ₂ ⁽⁵⁾${{where}\mspace{14mu} W_{p,n}^{(5)}} = {{\frac{1}{\sqrt{5}}\left\lbrack {W_{p,n}^{1,N_{g},2}\mspace{31mu} W_{p,n}^{2,N_{g},2}\mspace{31mu} W_{p,n}^{3,N_{g},2}\mspace{31mu} W_{p,n}^{4,N_{g},2}\mspace{31mu} W_{p,n}^{5,N_{g},2}} \right\rbrack}.}$

TABLE 63 Codebook for 6-layer CSI reporting using antenna ports [3000 to2999 + P_(CSI-RS)] Config1, (N_(g), N₁, N₂) = (4, 1, 1) i_(1,4,q), q =1, 2, 3 i₂ 0, 1, 2, 3 0, 1 W_(i) _(1,4) _(,i) ₂ ⁽⁶⁾${{where}\mspace{14mu} W_{p,n}^{(6)}} = {{\frac{1}{\sqrt{6}}\left\lbrack {W_{p,n}^{1,N_{g},1}\mspace{31mu} W_{p,n}^{2,N_{g},1}\mspace{31mu} W_{p,n}^{3,N_{g},1}\mspace{31mu} W_{p,n}^{4,N_{g},1}\mspace{31mu} W_{p,n}^{5,N_{g},1}\mspace{31mu} W_{p,n}^{6,N_{g},1}} \right\rbrack}.}$Config2, (N_(g), N₁, N₂) = (4, 1, 1) i_(1,4,q), q = 1, . . . , 6i_(2,q), q = 0, 1, . . . , 6 0, 1, 2, 3 0, 1 W_(i) _(1,4) _(,i) ₂ ⁽⁶⁾${{where}\mspace{14mu} W_{p,n}^{(6)}} = {{\frac{1}{\sqrt{6}}\left\lbrack {W_{p,n}^{1,N_{g},2}\mspace{31mu} W_{p,n}^{2,N_{g},2}\mspace{31mu} W_{p,n}^{3,N_{g},2}\mspace{31mu} W_{p,n}^{4,N_{g},2}\mspace{31mu} W_{p,n}^{5,N_{g},2}\mspace{31mu} W_{p,n}^{6,N_{g},2}} \right\rbrack}.}$

TABLE 64 Codebook for 7-layer CSI reporting using antenna ports [3000 to2999 + P_(CSI-RS)] Config1, (N_(g), N₁, N₂) = (4, 1, 1) i_(1,4,q), q =1, 2, 3 i₂ 0, 1, 2, 3 0, 1 W_(i) _(1,4) _(,i) ₂ ⁽⁷⁾${{where}\mspace{14mu} W_{p,n}^{(7)}} = {{\frac{1}{\sqrt{7}}\left\lbrack {W_{p,n}^{1,N_{g},1}\mspace{31mu} W_{p,n}^{2,N_{g},1}\mspace{31mu} W_{p,n}^{3,N_{g},1}\mspace{31mu} W_{p,n}^{4,N_{g},1}\mspace{31mu} W_{p,n}^{5,N_{g},1}\mspace{31mu} W_{p,n}^{6,N_{g},1}\mspace{31mu} W_{p,n}^{7,N_{g},1}} \right\rbrack}.}$Config2, (N_(g), N₁, N₂) = (4, 1, 1) i_(1,4,q), q = 1, . . . , 6i_(2,q), q = 0, 1, . . . , 6 0, 1, 2, 3 0, 1 W_(i) _(1,4) _(,i) ₂ ⁽⁷⁾${{where}\mspace{14mu} W_{p,n}^{(7)}} = {{\frac{1}{\sqrt{7}}\left\lbrack {W_{p,n}^{1,N_{g},2}\mspace{31mu} W_{p,n}^{2,N_{g},2}\mspace{31mu} W_{p,n}^{3,N_{g},2}\mspace{31mu} W_{p,n}^{4,N_{g},2}\mspace{31mu} W_{p,n}^{5,N_{g},2}\mspace{31mu} W_{p,n}^{6,N_{g},2}\mspace{31mu} W_{p,n}^{7,N_{g},2}} \right\rbrack}.}$

TABLE 65 Codebook for 8-layer CSI reporting using antenna ports [3000 to2999 + P_(CSI-RS)] Config1, (N_(g), N₁, N₂) = (4, 1, 1) i_(1,4,q), q =1, 2, 3 i₂ 0, 1, 2, 3 0, 1 W_(i) _(1,4) _(,i) ₂ ⁽⁸⁾$W_{p,n}^{(8)} = {{\frac{1}{\sqrt{8}}\left\lbrack {W_{p,n}^{1,N_{g},1}\mspace{31mu} W_{p,n}^{2,N_{g},1}\mspace{31mu} W_{p,n}^{3,N_{g},1}\mspace{31mu} W_{p,n}^{4,N_{g},1}\mspace{31mu} W_{p,n}^{5,N_{g},1}\mspace{31mu} W_{p,n}^{6,N_{g},1}\mspace{31mu} W_{p,n}^{7,N_{g},1}\mspace{31mu} W_{p,n}^{8,N_{g},1}} \right\rbrack}.}$Config2, (N_(g), N₁, N₂) = (4, 1, 1) i_(1,4,q), q = 1, . . . , 6i_(2,q), q = 0, 1, . . . , 6 0, 1, 2, 3 0, 1 W_(i) _(1,4) _(,i) ₂ ⁽⁸⁾$W_{p,n}^{(8)} = {{\frac{1}{\sqrt{8}}\left\lbrack {W_{p,n}^{1,N_{g},2}\mspace{31mu} W_{p,n}^{2,N_{g},2}\mspace{31mu} W_{p,n}^{3,N_{g},2}\mspace{31mu} W_{p,n}^{4,N_{g},2}\mspace{31mu} W_{p,n}^{5,N_{g},2}\mspace{31mu} W_{p,n}^{6,N_{g},2}\mspace{31mu} W_{p,n}^{7,N_{g},2}\mspace{31mu} W_{p,n}^{8,N_{g},2}} \right\rbrack}.}$

In one embodiment A5A, the pre-coding matrix expression in the 5 layercodebook TABLE 62 is replaced with one of following:

$\begin{matrix}{{W_{p,n}^{(5)} = {\frac{1}{\sqrt{5}}\begin{bmatrix}W_{p,n}^{c_{1},N_{g},1} & W_{p,n}^{c_{2},N_{g},1} & W_{p,n}^{c_{3},N_{g},1} & W_{p,n}^{c_{4},N_{g},1} & W_{p,n}^{c_{5},N_{g},1}\end{bmatrix}}};} & {{Config}\; 1}\end{matrix}$

and

$\begin{matrix}{W_{p,n}^{(5)} = {\frac{1}{\sqrt{5}}\begin{bmatrix}W_{p,n}^{c_{1},N_{g},2} & W_{p,n}^{c_{2},N_{g},2} & W_{p,n}^{c_{3},N_{g},2} & W_{p,n}^{c_{4},N_{g},2} & W_{p,n}^{c_{5},N_{g},2}\end{bmatrix}}} & {{Config}\; 2}\end{matrix}$

where (c₁,c₂, . . . , c₅) corresponds toone of

$\begin{pmatrix}8 \\5\end{pmatrix} = 56$

combinations of 5 numbers out of {1,2, . . . , 8}.

The pre-coding matrix expression in the 6 layer codebook TABLE 63 isreplaced with one of following:

$\begin{matrix}{{\mspace{680mu} {{{Config}1}{W_{p,n}^{(6)} =}}\quad} {\quad{\frac{1}{\sqrt{6}}{\quad {\left. \quad{\left\lbrack \quad \right. \begin{matrix}W_{p,n}^{c_{1},N_{g},1} & W_{p,n}^{c_{2},N_{g},1} & W_{p,n}^{c_{3},N_{g},1} & W_{p,n}^{c_{4},N_{g},1} & W_{p,n}^{c_{5},N_{g},1} & W_{p,n}^{c_{6},N_{g},1}\end{matrix}} \right\rbrack;\mspace{79mu} {a{nd}}}\mspace{70mu}}}}} & \; \\{\mspace{675mu} {{{Config}2}{W_{p,n}^{(6)} = {\frac{1}{\sqrt{6}}{\quad\left\lbrack \begin{matrix}W_{p,n}^{c_{1},N_{g},2} & W_{p,n}^{c_{2},N_{g},2} & W_{p,n}^{c_{3},N_{g},2} & W_{p,n}^{c_{4},N_{g},2} & W_{p,n}^{c_{5},N_{g},2} & W_{p,n}^{{c_{6},N_{g},2}}\end{matrix} \right\rbrack}}}}} & \;\end{matrix}$

where (c₁,c₂, . . . , c₆) corresponds to one of

$\begin{pmatrix}8 \\6\end{pmatrix} = 28$

combinations of 6 numbers out of {1,2, . . . ,8 }.

The pre-coding matrix expression in the 7 layer codebook TABLE 64 arereplaced with one of following:

$\begin{matrix}{\mspace{680mu} {{{{Config}1}W_{p,n}^{(7)}} = {\frac{1}{\sqrt{7}}{\quad{\left\lbrack {W_{p,n}^{c_{1},N_{g},1}W_{p,n}^{c_{2},N_{g},1}W_{p,n}^{c_{3},N_{g},1}W_{p,n}^{c_{4},N_{g},1}W_{p,n}^{c_{5},N_{g},1}W_{p,n}^{c_{6},N_{g},1}W_{p,n}^{c_{7},N_{g},1}} \right\rbrack ;\mspace{79mu} {{an}d}}}}}} & \; \\{\mspace{680mu} {{{{Config}2}W_{p,n}^{(7)}} = {\frac{1}{\sqrt{7}}{\quad\left\lbrack {W_{p,n}^{c_{1},N_{g},2}W_{p,n}^{c_{2},N_{g},2}W_{p,n}^{c_{3},N_{g},2}W_{p,n}^{c_{4},N_{g},2}W_{p,n}^{c_{5},N_{g},2}W_{p,n}^{c_{6},N_{g},2}W_{p,n}^{c_{7},N_{g},2}} \right\rbrack}}}} & \;\end{matrix}$

where (c₁,c₂, . . . , c₇) corresponds to one of

$\begin{pmatrix}8 \\7\end{pmatrix} = 8$

combinations of 7 numbers out of {1,2, . . . , 8}.

In one embodiment A6, the codebook table for (N_(g), N₁, N₂)=(1,1,1),i.e., single panel with 2 ports, is defined by PMI indices i_(1,4) andi₂, and quantities φ_(n), a_(p), and b_(n) as defined in embodimentA3/A4/A5. The pre-coding vector/matrix for 1-2 layer CSI reporting isaccording to one of the following alternatives. One of thesealternatives is either fixed in the standard specification or isconfigured via higher layer signaling.

In one example of Alt A6-0, if the UE is configured withCodebookMode=Config1, then the quantities W_(p,n) ^(1,N) ^(g) ^(,1) andW_(p,n) ^(2,N) ^(g) ^(,1) (N_(g)=1) are given by:

$W_{n}^{1,1,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n}\end{bmatrix}}\mspace{14mu} W_{n}^{2,1,1}} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}}\end{bmatrix}}.}}$

In such example, the pre-coding vector for 1-layer CSI reporting isgiven by W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) ₂ ^(1,1,1), where i_(1,4)=0 andi₂=0,1,2,3. In such example, the pre-coding matrix for 2-layer CSIreporting is given by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{2}}^{1,1,1} & W_{i_{2}}^{2,1,1}\end{bmatrix}}},$

where i_(1,4)=0 and i₂=0,1 .

In one example of Alt A6-1, if the UE is configured withCodebookMode=Config2, then the quantities W_(p,n) ^(1,N) ^(g) ^(,2) andW_(p,n) ^(2,N) ^(g) ^(,2) (N_(g)=1) are given by:

$W_{p,n}^{1,1,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{a_{p}b_{n}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,1,2}} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{{- a_{p}}b_{n}}\end{bmatrix}}.}}$

In such example, the pre-coding vector for 1-layer CSI reporting isgiven by W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) _(1,4) _(,i) ₂ ^(1,1,2), wherei_(1,4)=0,1,2,3 and i₂=0,1. In such example, the pre-coding matrix for2-layer CSI reporting is given by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,1,2} & W_{i_{1,4},i_{2}}^{2,1,2}\end{bmatrix}}},$

where i_(1,4)=0,1,2,3 and i₂=0,1.

In one example of Alt A6-2, if the UE is configured withCodebookMode=Config3, then the quantities W_(p,n) ^(1,N) ^(g) ^(,3) andW_(p,n) ^(2,N) ^(g) ^(,3) (N_(g)=1) are given by:

$W_{0}^{1,1,3} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\0\end{bmatrix}}\mspace{14mu} W_{1}^{1,1,3}} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}0 \\1\end{bmatrix}}.}}$

In such example, the pre-coding vector for 1-layer CSI reporting isgiven by W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) ₂ ^(1,1,3), where i_(1,4)=0 andi₂=0,1 . In such example, the pre-coding matrix for 2-layer CSIreporting is given by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{2}}^{1,1,3} & W_{i_{2} + 1}^{1,1,3}\end{bmatrix}}},$

where i_(1,4)=0 and i₂=0.

In one example of Alt A6-4, if the UE is configured withCodebookMode=Config4, then the pre-coder vector/matrix can be eitheraccording to Alt A6-0 or Alt A6-2 for all 1-2 layers. In such example,the pre-coding vector for 1-layer CSI reporting is given by W_(i) _(1,4)_(,i) ₂ ⁽¹⁾=W_(i) ₂ ^(1,1,1), where i_(1,4)=0 and i₂=0,1,2,3. In suchexample, the pre-coding vector for 1-layer CSI reporting is given byW_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) ₂ ⁻⁴ ^(1,1,3),where i_(1,4)=0 and i₂=4,5.In such example, the pre-coding matrix for 2-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{2}}^{1,1,1} & W_{i_{2}}^{2,1,1}\end{bmatrix}}},$

where j_(1,4)=0 and i₂=0,1 . In such example, the pre-coding matrix for2-layer CSI reporting is given by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{2} - 2}^{1,1,3} & W_{i_{2} - 1}^{1,1,3}\end{bmatrix}}},$

where i_(1,4)=0 and i₂=2.

In one example of Alt A6-5, if the UE is configured withCodebookMode=Config5, then the pre-coder vector/matrix can be eitheraccording to Alt A6-1 or Alt A6-2 for all 1-2 layers. In such example,the pre-coding vector for 1-layer CSI reporting is given by W_(i) _(1,4)_(,i) ₂ ⁽¹⁾=W_(i) _(1,4) _(,i) ₂ ^(1,1,2),where i_(1,4)=0,1,2,3 andi₂=0.1. In such example, the pre-coding vector for 1-layer CSI reportingis given by W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) ₂ ⁻² ^(1,1,3), wherei_(1,4)=0 and i₂=2,3. In such example, the pre-coding matrix for 2-layerCSI reporting is given by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,1,2} & W_{i_{1,4},i_{2}}^{2,1,2}\end{bmatrix}}},$

where i_(1,4)=0,1,2,3 and i₂=0,1. In such example, the pre-coding matrixfor 2-layer CSI reporting is given by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{2} - 2}^{1,1,3} & W_{i_{2} - 1}^{1,1,3}\end{bmatrix}}},$

where i_(1,4)=0 and i₂=2.

In one example of Alt A6-6, if the UE is configured withCodebookMode=Config6, then the pre-coder vector/matrix is according toAlt A6-x for 1-layer CSI reporting and according to Alt A6-y for 2-layerCSI reporting where x≠y. A few examples of x and y are as follows:(x,y)=(0, 2); (x, y)=(1, 2); (x, y)=(3, 2); and (x, y)=(4, 2)

In one embodiment A6A, at least one of the proposed 2 port codebook inembodiment A6 is also used for TPMI indication (in UL-related DCIsignaling) for codebook-based UL transmission. Two alternatives in thiscase are as follows. In one example of Alt A6A-1, the codebook is usedregardless of 2 ports being either on a single panel with 2dual-polarized antenna ports at the UE or two panels each with a singleantenna port at the UE. In one example of Alt A6A-2, the codebook isonly used for the case of two panels each with a single antenna port atthe UE.

In one embodiment A7, the codebook table for (N_(g),N₁,N₂)=(2,1,1),i.e., two panels each with 2 ports, is defined by PMI indices i_(1,4)and i₂, and quantities φ_(n), a_(p), and b_(n) as defined in embodimentA3A/4/A5. The pre-coding vector/matrix for 1-4 layer CSI reporting isaccording to one of the following alternatives. One of thesealternatives is either fixed in the specification or is configured viahigher layer signaling.

In one example of Alt A7-0, if the UE is configured withCodebookMode=Config1, then the following quantities are defined as givenby:

$W_{p,n}^{1,2,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\\phi_{p_{1}} \\{\phi_{n}\phi_{p_{1}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,2,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\\phi_{p_{1}} \\{{- \phi_{n}}\phi_{p_{1}}}\end{bmatrix}}}$$W_{p,n}^{3,2,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\{- \phi_{p_{1}}} \\{{- \phi_{n}}\phi_{p_{1}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,2,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\{- \phi_{p_{1}}} \\{\phi_{n}\phi_{p_{1}}}\end{bmatrix}}}$ where  p = p₁.

In such example, the pre-coding vector for 1-layer CSI reporting isgiven by W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) _(1,4) _(,i) ₂ ^(1,2,1), wherethe range of values for i_(1,4) and i₂ (or/and their components) aredefined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 1-layer CSI reporting.

In such example, the pre-coding matrix for 2-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,2,1} & W_{i_{1,4},i_{2}}^{2,2,1}\end{bmatrix}}},$

where the range of values for i_(1,4) and i₂ (or/and their components)are defined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 2-layer CSI reporting.

In such example, the pre-coding matrix for 3-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,2,1} & W_{i_{1,4},i_{2}}^{2,2,1} & W_{i_{1,4},i_{2}}^{3,2,1}\end{bmatrix}}},$

where the range of values for i_(1,4) and i₂ (or/and their components)are defined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 3-layer CSI reporting.

In such example, the pre-coding matrix for 4-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,2,1} & W_{i_{1,4},i_{2}}^{2,2,1} & W_{i_{1,4},i_{2}}^{3,2,1} & W_{i_{1,4},i_{2}}^{4,2,1}\end{bmatrix}}},$

where the range of values for i_(1,4) and i₂ (or/and their components)are defined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 4-layer CSI reporting.

In one example of Alt A7-1, if the UE is configured withCodebookMode=Config2, then the following quantities are defined as givenby:

$W_{p,n}^{1,2,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{a_{p_{1}}b_{n_{1}}} \\{a_{p_{2}}b_{p_{2}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,2,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{a_{p_{1}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{p_{2}}}\end{bmatrix}}}$$W_{p,n}^{3,2,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{p_{2}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,2,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{a_{p_{2}}b_{p_{2}}}\end{bmatrix}}}$ where $p = \begin{bmatrix}p_{1} & p_{2}\end{bmatrix}$ $n = {\begin{bmatrix}n_{0} & n_{1} & n_{2}\end{bmatrix}.}$

In such example, the pre-coding vector for 1-layer CSI reporting isgiven by W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) _(1,4) _(,i) ₂ ^(1,2,2), wherethe range of values i_(1,4) and i₂ (or/and their components) are definedas in embodiment A4 (or A4A or A4B or A4C or A4D or their combination)for 1-layer CSI reporting.

In such example, the pre-coding matrix for 2-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,2,2} & W_{i_{1,4},i_{2}}^{2,2,2}\end{bmatrix}}},$

where the range of values for i_(1,4) and i₂ (or/and their components)are defined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 2-layer CSI reporting.

In such example, the pre-coding matrix for 3-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}\begin{matrix}W_{i_{1,4},i_{2}}^{1,2,2} & W_{i_{1,4},i_{2}}^{2,2,2}\end{matrix} & W_{i_{1,4},i_{2}}^{3,2,2}\end{bmatrix}}},$

where the range of values for i_(1,4) and i₂ (or/and their components)are defined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 3-layer CSI reporting.

In such example, the pre-coding matrix for 4-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}\begin{matrix}W_{i_{1,4},i_{2}}^{1,2,2} & W_{i_{1,4},i_{2}}^{2,2,2}\end{matrix} & W_{i_{1,4},i_{2}}^{3,2,2} & W_{i_{1,4},i_{2}}^{4,2,2}\end{bmatrix}}},$

where the range of values for i₁₄ and i₂ (or/and their components) aredefined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 4-layer CSI reporting.

In one example of Alt A7-2, if the UE is configured withCodebookMode=Config3, then the following quantities are defined as givenby:

$W_{n}^{1,2,3} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\0 \\0\end{bmatrix}}\mspace{14mu} W_{n}^{2,2,3}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\0 \\0\end{bmatrix}}}$$W_{n}^{3,2,3} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}0 \\0 \\1 \\\phi_{n}\end{bmatrix}}\mspace{14mu} W_{n}^{4,2,3}} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}0 \\0 \\1 \\{- \phi_{n}}\end{bmatrix}}.}}$

In such example, the pre-coding vector for 1-layer CSI reporting isgiven by W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) ₂ ^(1,2,3), where i_(1,4)=0 andi₁=0,1,2,3.

In such example, the pre-coding matrix for 2-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{2}}^{1,2,3} & W_{i_{2}}^{2,2,3}\end{bmatrix}}},$

where i_(1,4)=0 and i₂=0,1 .

In such example, the pre-coding matrix for 3-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}\begin{matrix}W_{i_{2,0}}^{1,2,3} & W_{i_{2,0}}^{2,2,3}\end{matrix} & W_{i_{2,1}}^{3,2,3}\end{bmatrix}}},$

where i_(1,4)=0 and ^(i) ₂=[i_(2,0) i_(2,1)], where i_(2,q)=0,1, isreported according to at least one of the following options: Option 0:i_(2.0)=i_(2.1) is reported common for both panels; and Option i_(2.0)and i_(2.1) are reported independently for both panels.

In such example, the pre-coding matrix for 4-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}\begin{matrix}W_{i_{2,0}}^{1,2,3} & W_{i_{2,0}}^{2,2,3}\end{matrix} & W_{i_{2,1}}^{3,2,3} & W_{i_{2,1}}^{4,2,3}\end{bmatrix}}},$

where, i_(1,4)=0 and ^(i) ₂=[^(i) _(2,0) i_(2,1)], where i_(2,q)=0,1, isreported according to at least one of the following options: Option 0:i_(2,0)=i_(2,1) is reported common for both panels; and Option 1:i_(2,0) and i_(2,1) are reported independently for both panels.

In one example of Alt A7-2A, if the UE is configured withCodebookMode=Config3A, then the following quantities are defined asgiven by:

$W_{p,n}^{1,2,3} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{a_{p}b_{n}} \\0 \\0\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,2,3}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{{- a_{p}}b_{n}} \\0 \\0\end{bmatrix}}}$$W_{p,n}^{3,2,3} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}0 \\0 \\1 \\{a_{p}b_{n}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,2,3}} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}0 \\0 \\1 \\{{- a_{p}}b_{n}}\end{bmatrix}}.}}$

In such example, the pre-coding vector for 1-layer CSI reporting isgiven by W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) _(1,4) _(,i) ₂ ^(1,2,3), wherei_(1,3)=0,1,2,3 and i₁=0,1,2,3.

In such example, the pre-coding matrix for 2-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,2,3} & W_{i_{1,4},i_{2}}^{2,2,3}\end{bmatrix}}},$

where i_(1,4)=0.1.2.3 and i₂=0,1.

In such example, the pre-coding matrix for 3-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{i_{1,4,0},i_{2,0}}^{1,2,3} & W_{i_{1,4,0},i_{2,0}}^{2,2,3} & W_{i_{1,4,1},i_{2,1}}^{3,2,3}\end{bmatrix}}},$

where i_(1,4)=[i_(1,4,0) i_(1,4,1)] and i₂=[i_(2,0) i^(2,1)], wherei_(1,4,q)=0,1,2,3 and i_(2,q)=0,1, are reported according to at leastone of the following options: Option 0: i_(1,4,0)=i_(1,4,1) or/andi_(2,0)=i_(2,) is/are reported common for both panels; and Option 1:i_(1,4,0),i_(1,4,1), i_(2,0), and i_(2,1) are reported independently forboth panels.

In such example, the pre-coding matrix for 4-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}W_{i_{1,4,0},i_{2,0}}^{1,2,3} & W_{i_{1,4,0},i_{2,0}}^{2,2,3} & W_{i_{1,4,1},i_{2,1}}^{3,2,3} & W_{i_{1,4,1},i_{2,1}}^{4,2,3}\end{bmatrix}}},$

where i_(1,4)=[i_(1,4,0) i_(1,4,1)] and i₂=[i_(2,0) i_(2,1)],i_(1,4,q)=0,1,2,3 and i_(2,q)=0,1, are reported according to at leastone of the following options: Option 0: i_(1,4,0)=1_(1,4,1) or/andi_(2,0)=i_(2,1) is/are reported common for both panels; and Option 1:i_(1,4,0), i_(1,4,1), i_(2,0), and i_(2,1) are reported independentlyfor both panels.

In one example of Alt A7-4, if the UE is configured withCodebookMode=Config4, then the pre-coder vector/matrix can be eitheraccording to Alt A7-0 or Alt A7-2/A7-2A for all 1-4 layers.

In such example, the codebook for 1-layer CSI reporting is a union ofthe 1-layer codebook according to Alt A7-0 and the 1-layer codebookaccording to Alt A7-2/A7-2A.

In such example, the codebook for 2-layer CSI reporting is a union ofthe 2-layer codebook according to Alt A7-0 and the 2-layer codebookaccording to Alt A7-2/A7-2A.

In such example, the codebook for 3-layer CSI reporting is a union ofthe 3-layer codebook according to Alt A7-0 and the 3-layer codebookaccording to Alt A7-2/A7-2A.

In such example, the codebook for 4-layer CSI reporting is a union ofthe 4-layer codebook according to Alt A7-0 and the 4-layer codebookaccording to Alt A7-2/A7-2A.

In one example of Alt A7-5, if the UE is configured withCodebookMode=Config5, then the pre-coder vector/matrix can be eitheraccording to Alt A7-1 or Alt A7-2/A7-2A for all 1-4 layers.

In such example, the codebook for 1-layer CSI reporting is a union ofthe 1-layer codebook according to Alt A7-1 and the 1-layer codebookaccording to Alt A7-2/A7-2A.

In such example, the codebook for 2-layer CSI reporting is a union ofthe 2-layer codebook according to Alt A7-1 and the 2-layer codebookaccording to Alt A7-2/A7-2A.

In such example, the codebook for 3-layer CSI reporting is a union ofthe 3-layer codebook according to Alt A7-1 and the 3-layer codebookaccording to Alt A7-2/A7-2A.

In such example, the codebook for 4-layer CSI reporting is a union ofthe 4-layer codebook according to Alt A7-1 and the 4-layer codebookaccording to Alt A7-2/A7-2A.

In one example of Alt A7-6, if the UE is configured withCodebookMode=Config6, then the pre-coder vector/matrix is according toAlt A7-x for 1 to r layer CSI reporting and according to Alt A7-y forr+1 to 4 layer CSI reporting where x≠y, and r=1 or 2. A few examples ofx and y are as follows: (x, y)=(0, 2) or (0, 2A); (x, y)=(1, 2) or (1,2A); (x, y)=(3, 2) or (3, 2A); and (x, y)=(4, 2) or (4, 2A).

In one embodiment A7A, at least one of the proposed 4 port codebook inembodiment A7 is also used for TPMI indication (in UL-related DCIsignaling) for codebook-based UL transmission. Two alternatives in thiscase are as follows. In one example of Alt A7A-1, the codebook is usedregardless of 4 ports being either on a single panel (N_(g)=1) with 4single-polarized or dual-polarized antenna ports at the UE or on twopanels (N_(g)=2) each with 2 antenna ports at the UE. In one example ofAlt A7A-2, the codebook is only used for the case of two panels(N_(g)=2) each with 2 antenna ports at the UE.

In one embodiment A8, the codebook table for (N_(g),N₁,N₂)=(4,1,1),i.e., two panels each with 2 ports, is defined by PMI indices i_(1,4)and i₂, and quantities φ_(n), a_(p), and b_(n) as defined in embodimentA3/A4/A5. The pre-coding vector/matrix for 1-4 layer CSI reporting isaccording to one of the following alternatives. One of thesealternatives is either fixed in the specification or is configured viahigher layer signaling.

In one example of Alt A8-0, if the UE is configured withCodebookMode=Config1, then the following quantities are defined as givenby:

$W_{p,n}^{1,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\\phi_{p_{1}} \\{\phi_{n}\phi_{p_{1}}} \\\phi_{p_{2}} \\{\phi_{n}\phi_{p_{2}}} \\\phi_{p_{3}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\\phi_{p_{1}} \\{{- \phi_{n}}\phi_{p_{1}}} \\\phi_{p_{2}} \\{{- \phi_{n}}\phi_{p_{2}}} \\\phi_{p_{3}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}}$$W_{p,n}^{3,4,1} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\{- \phi_{p_{1}}} \\{{- \phi_{n}}\phi_{p_{1}}} \\\phi_{p_{2}} \\{\phi_{n}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{{- \phi_{n}}\phi_{p_{3}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,1}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\{- \phi_{p_{1}}} \\{\phi_{n}\phi_{p_{1}}} \\\phi_{p_{2}} \\{{- \phi_{n}}\phi_{p_{2}}} \\{- \phi_{p_{3}}} \\{\phi_{n}\phi_{p_{3}}}\end{bmatrix}}}$ ${{where}\mspace{14mu} p} = {\begin{bmatrix}p_{1} & p_{2} & p_{3}\end{bmatrix}.}$

In such example, the pre-coding vector for 1-layer CSI reporting isgiven by W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) _(1,4) _(,i) ₂ ^(1,4,1), wherethe range of values for i_(1,4) and i₂ (or/and their components)aredefined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 1-layer CSI reporting.

In such example, the pre-coding matrix for 2-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,4,1} & W_{i_{1,4},i_{2}}^{2,4,1}\end{bmatrix}}},$

where the range of values for i_(1,4) and i₂ (or/and their components)are defined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 2-layer CSI reporting.

In such example, the pre-coding matrix for 3-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,4,1} & W_{i_{1,4},i_{2}}^{2,4,1} & W_{i_{1,4},i_{2}}^{3,4,1}\end{bmatrix}}},$

where the range of values for i_(1,4) and i₂ (or/and their components)are defined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 3-layer CSI reporting.

In such example, the pre-coding matrix for 4-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}\begin{matrix}W_{i_{1,4},i_{2}}^{1,4,1} & W_{i_{1,4},i_{2}}^{2,4,1} & W_{i_{1,4},i_{2}}^{3,4,1}\end{matrix} & W_{i_{1,4},i_{2}}^{4,4,1}\end{bmatrix}}},$

where the range of values for i_(1,4) and i₂ (or/and their components)are defined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 4-layer CSI reporting.

In one example of Alt A8-1, if the UE is configured withCodebookMode=Config2, then the following quantities are defined as givenby:

$W_{p,n}^{1,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{a_{p_{1}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{a_{p_{1}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{a_{p_{5}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}}$$W_{p,n}^{3,4,2} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{a_{p_{4}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{{- a_{p_{6}}}b_{n_{6}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,2}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{{- a_{p_{1}}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\{a_{p_{3}}b_{n_{3}}} \\{{- a_{p_{4}}}b_{n_{4}}} \\{{- a_{p_{5}}}b_{n_{5}}} \\{a_{p_{6}}b_{n_{6}}}\end{bmatrix}}}$ where $p = \begin{bmatrix}p_{1} & p_{2} & p_{3} & p_{4} & p_{5} & p_{6}\end{bmatrix}$ $n = {\begin{bmatrix}n_{1} & n_{2} & n_{3} & n_{4} & n_{5} & n_{6}\end{bmatrix}.}$

In such example, the pre-coding vector for 1-layer CSI reporting isgiven by W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) _(1,4) _(,i) ₂ ^(1,4,2), wherethe range of values for i_(1,4) and i₂ (or/and their components) aredefined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 1-layer CSI reporting.

In such example, the pre-coding matrix for 2-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,4,2} & W_{i_{1,4},i_{2}}^{2,4,2}\end{bmatrix}}},$

where the range of values for i_(1,4) and i₂ (or/and their components)are defined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 2-layer CSI reporting.

In such example, the pre-coding matrix for 3-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,4,2} & W_{i_{1,4},i_{2}}^{2,4,2} & W_{i_{1,4},i_{2}}^{3,4,2}\end{bmatrix}}},$

where the range of values for i_(1,4) and i₂ (or/and their components)are defined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 3-layer CSI reporting.

In such example, the pre-coding matrix for 4-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}\begin{matrix}W_{i_{1,4},i_{2}}^{1,4,2} & W_{i_{1,4},i_{2}}^{2,4,2} & W_{i_{1,4},i_{2}}^{3,4,2}\end{matrix} & W_{i_{1,4},i_{2}}^{4,4,2}\end{bmatrix}}},$

where the range of values for i_(1,4) and i₂ (or/and their components)are defined as in embodiment A4 (or A4A or A4B or A4C or A4D or theircombination) for 4-layer CSI reporting.

In one example of Alt A8-2, if the UE is configured withCodebookMode=Config3, then the following quantities are defined as givenby:

$W_{p,n}^{1,4,3} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n} \\\phi_{p} \\{\phi_{n}\phi_{p}} \\0 \\0 \\0 \\0\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,3}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n}} \\\phi_{p} \\{{- \phi_{n}}\phi_{p}} \\0 \\0 \\0 \\0\end{bmatrix}}}$$W_{p,n}^{3,4,3} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}0 \\0 \\0 \\0 \\1 \\\phi_{n} \\\phi_{p} \\{\phi_{n}\phi_{p}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,3}} = {{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}0 \\0 \\0 \\0 \\1 \\{- \phi_{n}} \\\phi_{p} \\{{- \phi_{n}}\phi_{p}}\end{bmatrix}}.}}$

In such example, the pre-coding vector for 1-layer CSI reporting isgiven by W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) _(1,4) _(,i) ₂ ^(1,4,3), wherei_(1,4)=0,1,2,3 and i₂=0,1,2,3.

In such example, the pre-coding matrix for 2-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,4,3} & W_{i_{1,4},i_{2}}^{2,4,3}\end{bmatrix}}},$

where i_(1,4)=0,1,2,3 and i₂=0,1.

In such example, the pre-coding matrix for 3-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{i_{1,4,0},i_{2,0}}^{1,4,3} & W_{i_{1,4,0},i_{2,0}}^{2,4,3} & W_{i_{1,4,1},i_{2,1}}^{3,4,3}\end{bmatrix}}},$

where i_(1,4)=[i_(1,4,0) i_(1,4,1)] and i₂=[i_(2,0) i_(2,1)], wherei_(1,4,q)=0,1,2,3 and i_(2,q)=0,1, are reported according to at leastone of the following options: Option 0: i_(1,4,0)=i_(1,4,1) or/andi_(2,0)=i_(2,1) is/are reported common for the pair of 2 panels; andOption 1: i_(1,4,0), i_(1,4,1), i_(2,0), and i_(2,1) are reportedindependently for the pair of 2 panels.

In such example, the pre-coding matrix for 4-layer CSI reporting isgiven by

${W_{i_{1,4},i_{2}}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}W_{i_{1,4,0},i_{2,0}}^{1,4,3} & W_{i_{1,4,0},i_{2,0}}^{2,4,3} & W_{i_{1,4,1},i_{2,1}}^{3,4,3} & W_{i_{1,4,1},i_{2,1}}^{4,4,3}\end{bmatrix}}},$

where i_(1,4)=[i_(1,4,0) i_(1,4,1)] and ^(i) ₂=[i_(2,0) i_(2,1)], wherei_(1,4,q)=0,1,2,3 and i_(2,q)=0,1, are reported according to at leastone of the following options: Option 0: i_(1,4,0)=i_(1,4,1) or/andi_(2,0)=i_(2,1) is/are reported common for the pair of 2 panels; andOption 1: i_(1,4,0), i_(1,4,1), i_(2,0), and i_(2,1) are reportedindependently for the pair of 2 panels.

In one example of Alt A8-2A, if the UE is configured withCodebookMode=Config3A, then the following quantities are defined asgiven by:

$W_{p,n}^{1,4,3} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\\phi_{n_{0}} \\{a_{p_{1}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}} \\0 \\0 \\0 \\0\end{bmatrix}}\mspace{14mu} W_{p,n}^{2,4,3}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}1 \\{- \phi_{n_{0}}} \\{a_{p_{1}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}} \\0 \\0 \\0 \\0\end{bmatrix}}}$$W_{p,n}^{3,4,3} = {{{\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}0 \\0 \\0 \\0 \\1 \\\phi_{n_{0}} \\{a_{p_{1}}b_{n_{1}}} \\{a_{p_{2}}b_{n_{2}}}\end{bmatrix}}\mspace{14mu} W_{p,n}^{4,4,3}} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}0 \\0 \\0 \\0 \\1 \\{- \phi_{n_{0}}} \\{a_{p_{1}}b_{n_{1}}} \\{{- a_{p_{2}}}b_{n_{2}}}\end{bmatrix}}}$ where $p = \begin{bmatrix}p_{1} & p_{2}\end{bmatrix}$ $n = {\begin{bmatrix}n_{0} & n_{1} & n_{2}\end{bmatrix}.}$

In one example, the pre-coding vector for 1-layer CSI reporting is givenby W_(i) _(1,4) _(,i) ₂ ⁽¹⁾=W_(i) _(1,4) _(,i) ₂ ^(1,4,3), wherei_(1,4)=[i_(1,4,0) i_(1,4,1)] and i₂=[i_(2,0) i_(2,1) i_(2,2)], wherei_(1,4,q)=0,1,2,3 and i_(2,q)=0,1.

In one example, the pre-coding matrix for 2-layer CSI reporting is givenby

${W_{i_{1,4},i_{2}}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{i_{1,4},i_{2}}^{1,4,3} & W_{i_{1,4},i_{2}}^{2,4,3}\end{bmatrix}}},$

where i_(1,4)=[i_(1,4,0) i_(1,4,1)] and i₂=[i_(2,0) i_(2,1) i_(2,2)],where i_(1,4,q)=0,1,2,3 and i_(2,q)=0,1.

In one example, the pre-coding matrix for 3-layer CSI reporting is givenby

${W_{i_{1,4},i_{2}}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{i_{1,4,0},i_{2,0}}^{1,4,3} & W_{i_{1,4,0},i_{2,0}}^{2,4,3} & W_{i_{1,4,1},i_{2,1}}^{3,4,3}\end{bmatrix}}},$

where i_(1,4,q)=[i_(1,4,q,0) i_(1,4,q,1)] and i_(2,q)=[i_(2,q,0)i_(2,q,1) i_(2,q,2)], where i_(1,4,q,1)=0,1,2,3 and i_(2,q,1)=0,1, arereported according to at least one of the following options: Option 0:i_(1,4,q,0)=i_(1,4,q,1) or/and i_(2,q,0)=i_(2,q,1) is/are reportedcommon for both panels; and Option 1: i_(1,4,q,0), i_(1,4,q,1),i_(2,q,0), and i_(2,q,1) are reported independently for both panels.

In one example, the pre-coding matrix for 4-layer CSI reporting is givenby

${W_{i_{1,4},i_{2}}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}W_{i_{1,4,0},i_{2,0}}^{1,4,3} & W_{i_{1,4,0},i_{2,0}}^{2,4,3} & W_{i_{1,4,1},i_{2,1}}^{3,4,3} & W_{i_{1,4,1},i_{2,1}}^{4,4,3}\end{bmatrix}}},$

where i_(1,4,q)=[i_(1,4,q,0) i_(1,4,q,1)] and i_(2,q)=[i_(2,q,0)i_(2,q,1) i_(2,q,2)], where i_(1,4,q,r)=0,1,2,3 and i_(2,q,r)=0,1, arereported according to at least one of the following options: Option 0:i_(1,4,q,0)=i_(1,4,q,1) or/and i_(2,q,0)=i_(2,q,1) is/are reportedcommon for both panels; and Option 1: i_(1,4,q,0), i_(1,4,q,1),i_(2,q,0,) and i_(2,q,1) are reported independently for both panels.

In one example of Alt A8-4, if the UE is configured withCodebookMode=Config4, then the pre-coder vector/matrix can be eitheraccording to Alt A8-0 or Alt A8-2/A8-2A for all 1-4 layers.

In such example, the codebook for 1-layer CSI reporting is a union ofthe 1-layer codebook according to Alt A8-0 and the 1-layer codebookaccording to Alt A8-2/A8-2A.

In such example, the codebook for 2-layer CSI reporting is a union ofthe 2-layer codebook according to Alt A8-0 and the 2-layer codebookaccording to Alt A8-2/A8-2A.

In such example, the codebook for 3-layer CSI reporting is a union ofthe 3-layer codebook according to Alt A8-0 and the 3-layer codebookaccording to Alt A8-2/A8-2A.

In such example, the codebook for 4-layer CSI reporting is a union ofthe 4-layer codebook according to Alt A8-0 and the 4-layer codebookaccording to Alt A8-2/A8-2A.

In one example of Alt A8-5, if the UE is configured withCodebookMode=Config5, then the pre-coder vector/matrix can be eitheraccording to Alt A8-1 or Alt A8-2/A8-2A for all 1-4 layers.

In such example, the codebook for 1-layer CSI reporting is a union ofthe 1-layer codebook according to Alt A8-1 and the 1-layer codebookaccording to Alt A8-2/A8-2A.

In such example, the codebook for 2-layer CSI reporting is a union ofthe 2-layer codebook according to Alt A8-1 and the 2-layer codebookaccording to Alt A8-2/A8-2A.

In such example, the codebook for 3-layer CSI reporting is a union ofthe 3-layer codebook according to Alt A8-1 and the 3-layer codebookaccording to Alt A8-2/A8-2A.

In such example, the codebook for 4-layer CSI reporting is a union ofthe 4-layer codebook according to Alt A8-1 and the 4-layer codebookaccording to Alt A8-2/A8-2A.

In one example of Alt A8-6, if the UE is configured withCodebookMode=Config6, then the pre-coder vector/matrix is according toAlt A8-x for 1 to r layer CSI reporting and according to Alt A8-y forr+1 to 4 layer CSI reporting where x≠y, and r=1 or 2 or 4. A fewexamples of x and y is as follows: (x, y)=(0, 2) or (0, 2A); (x, y)=(1,2) or (1, 2A); (x, y)=(3, 2) or (3, 2A); and (x, y)=(4, 2) or (4, 2A).

In one embodiment A8A, at least one of the proposed 4 port codebook inembodiment A8 is also used for TPMI indication (in UL-related DCIsignaling) for codebook-based UL transmission. Two alternatives in thiscase are as follows. In one example of Alt A8A-1, the codebook is usedregardless of 8 ports being either on a single panel (N_(g)=1) with 8single-polarized or dual-polarized antenna ports at the UE or 2 panelseach with 4 antenna ports at the UE or on two panels (N_(g)=4) each with2 antenna ports at the UE.

In one example of Alt A8A-2, the codebook is only used for the case offour panels (N_(g)=4) each with 2 antenna ports at the UE.

FIG. 14 illustrates a flow chart of a method 1400 for CSI feedbackaccording to embodiments of the present disclosure, as may be performedby a user equipment (UE). The embodiment of the method 1400 illustratedin FIG. 14 is for illustration only. FIG. 14 does not limit the scope ofthis disclosure to any particular implementation.

As illustrated in FIG. 14, the method 1400 begins at step 1405. At step1405, the UE receives, from a base station (BS), configurationinformation for the CSI feedback. At step 1405, the configurationinformation indicates a number of antenna panels (N_(g)) at the BS and acodebook mode, wherein N_(g)>1 and each of the antenna panels comprisesantenna ports with a first polarization (P₁) and antenna ports with asecond polarization (P₂).

At step 1410, the UE identifies the number of antenna panels (N_(g)) atthe BS. At step 1415, the UE identifies a codebook for the CSI feedbackbased on the codebook mode configured between a first codebook mode anda second codebook mode.

In one embodiment, the number of antenna panels (N_(g)) is two or four.In one example, if the number of antenna panels is two (N_(g)=2), one ofthe first codebook mode or the second codebook mode is configured. Inone example, if the number of antenna panels is four (N_(g)=4), only thefirst codebook mode is configured.

In one embodiment, the number of antenna panels is two (N_(g)=2), thesecond codebook mode is configured, the wideband inter-panel co-phasefor each polarization (P_(i)) of a second of the two antenna panels isgiven by a_(p)=e^(jπ/4)e^(jπp/2), and the subband inter-panel co-phasefor each polarization (P_(i)) of the second antenna panel is given byb_(n)=e^(−jπ/4)e^(jπn/2), where p=0,1, 2, 3 and n=0,1.

In one embodiment, a combination of (N_(g),N₁,N₂), configured via theconfiguration information for the CSI feedback, for a given number ofantenna ports and corresponding values of (O₁, O₂) are determinedaccording to:

Number of antenna ports (N_(g), N₁, N₂) (O₁, O₂) 8 (2, 2, 1) (4, 1) 16(2, 4, 1) (4, 1) (4, 2, 1) (4, 1) (2, 2, 2) (4, 4) 32 (2, 8, 1) (4, 1)(4, 4, 1) (4, 1) (2, 4, 2) (4, 4) (4, 2, 2) (4, 4), where N₁ and N₂ respectively are a number of antenna ports with apolarization (P₁ or P₂) in first and second dimensions of each of theantenna panels, and O₁ and O₂ are oversampling factors in the first andsecond dimensions, respectively, and N₁, N₂, O₁ and O₂ are used toobtain a set of two-dimensional discrete Fourier transform (DFT) beams,v_(l,m), where l=0,1, . . . , O₁N₁N₁,

m = 0, 1, …  , O₂N₂, and   $u_{m} = \left\{ {{\begin{matrix}\begin{bmatrix}1 & e^{j\frac{2\; \pi \; m}{O_{2}N_{2}}} & \ldots & e^{j\frac{2\; \pi \; {m{({N_{2} - 1})}}}{O_{2}N_{2}}}\end{bmatrix} & {N_{2} > 1} \\1 & {N_{2} = 1}\end{matrix}.v_{l,m}} = \begin{bmatrix}u_{m} & {e^{j\frac{2\; \pi \; l}{O_{1}N_{1}}}u_{m}} & \ldots & {e^{j\frac{2\; \pi \; {l{({N_{1} - 1})}}}{O_{1}N_{1}}}u_{m}}\end{bmatrix}^{T}} \right.$

In various embodiments, for the first codebook mode, the codebook forgenerating the CSI feedback for N_(g)=2,4 is constructed using vectors:

${W_{l,m,p,n}^{1,2,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}}\end{bmatrix}}},{W_{l,m,p,n}^{2,2,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}}\end{bmatrix}}},{W_{l,m,p,n}^{1,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}},{W_{l,m,p,n}^{2,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}},;$ ${{where}\mspace{14mu} p} = \left\{ {\begin{matrix}p_{1} & {N_{g} = 2} \\\begin{bmatrix}p_{1} & p_{2} & p_{3}\end{bmatrix} & {N_{g} = 4}\end{matrix},} \right.$

and for the second codebook mode, the codebook for generating the CSIfeedback for N_(g)=2 is constructed using vectors:

${W_{l,m,p,n}^{1,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}}\end{bmatrix}}},{W_{l,m,p,n}^{2,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}}\end{bmatrix}}},{{where}\text{:}\mspace{14mu} \begin{matrix}{p = \begin{bmatrix}p_{1} & p_{2}\end{bmatrix}} \\{n = \begin{bmatrix}n_{0} & n_{1} & n_{2}\end{bmatrix}}\end{matrix}},$

n, n₀=0,1,2,3; p_(l), p₂, p₃=0,1,2,3; n₁,n₂=0,1; and P_(CSI-RS) is thenumber of antenna ports, andφ_(n)=e^(jπn/2)a_(p)=e^(jπ/4)e^(jπp/2)b_(n)=e^(−jπ/4)e^(jπn/2)

At step 1420, the UE generates the CSI feedback using the identifiedcodebook. In one embodiment, the CSI feedback includes a pre-codingmatrix indicator (PMI) that includes PMI indices i_(1,1), i_(1,2),i_(1,3), i_(1,4), and i₂.

In one example for 1-layer CSI feedback: for the first codebook mode,the codebook comprises pre-coding matrices: W_(l,m,p,n) ⁽¹⁾=W_(l,m,p,n)^(1,N) ^(g) ^(,1), and for the second codebook mode, the codebookcomprises pre-coding matrices: W_(l,m,p,n) ⁽¹⁾=W_(l,m,p,n) ^(1,N) ^(g)^(,2).

In one example for 2-layer CSI feedback: for the first codebook mode,the codebook comprises pre-coding matrices:

${W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1}\end{bmatrix}}},$

and for the second codebook mode, the codebook comprises pre-codingmatrices:

$W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {{\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2}\end{bmatrix}}.}$

In one example for 3-layer CSI feedback: for the first codebook mode,the codebook comprises pre-coding matrices:

${W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}\begin{matrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},1}\end{matrix} & W_{l,m,p,n}^{2,N_{g},1}\end{bmatrix}}},$

and for the second codebook mode, the codebook comprises pre-codingmatrices:

$W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {{\frac{1}{\sqrt{3}}\begin{bmatrix}\begin{matrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},2}\end{matrix} & W_{l,m,p,n}^{2,N_{g},2}\end{bmatrix}}.}$

In one example for 4-layer CSI feedback: for the first codebook mode,the codebook comprises pre-coding matrices:

${W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}\begin{matrix}\begin{matrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},1}\end{matrix} & W_{l,m,p,n}^{2,N_{g},1}\end{matrix} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1}\end{bmatrix}}},$

and for the second codebook mode, the codebook comprises pre-codingmatrices:

$W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}\begin{matrix}\begin{matrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},2}\end{matrix} & W_{l,m,p,n}^{2,N_{g},2}\end{matrix} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2}\end{bmatrix}}$

where: l=i_(1,1), m=i_(1,2), l′=i_(1,1)+k₁, m′=i_(1,2)+k₂, for the firstcodebook mode,

$p = \left\{ {\begin{matrix}{{p_{1} = {i_{1,4,1} = i_{1,4}}},} & {N_{g} = 2} \\{{\begin{bmatrix}p_{1} & p_{2} & p_{3}\end{bmatrix} = {\begin{bmatrix}i_{1,4,1} & i_{1,4,2} & i_{1,4,3}\end{bmatrix} = i_{1,4}}},} & {N_{g} = 4}\end{matrix},} \right.$

and n=i₂, for the second codebook mode, N_(g)=2, p=[p₁ p₂]=[i_(1,4,1)i_(1,4,2)]=i_(1,4), and n=[n₀ n₁ n₂]=[i_(2,0) i_(2,1) i_(2,2)]=i₂,i_(1,1) and i_(1,2) are PMI indices that indicate a first beam v_(i)_(1,1) _(,i) _(1,2) _(, i) _(1,3) is a PMI index that indicates adistance (k₁, k₂) of a second beam v_(i) _(1,1) _(+k) ₁ _(,i) _(1,2)_(+k) ₂ with respect to the first beam v_(i) _(1,1) _(,i) _(1,2) _(, i)_(1,4) is a PMI index that indicates the wideband inter-panel co-phase,and i₂ is a PMI index that indicates: for the first codebook mode, asubband co-phase between two polarizations is common for all of theantenna panels, and for the second codebook mode, the subband co-phasebetween two polarizations of a first of the antenna panels (viai_(2,0)), and the subband inter-panel co-phase for each polarization asecond of the antenna panels (via i_(2,1), i_(2,2)).

At step 1425, the UE transmits the generated CSI feedback to the BS. Inone embodiment, at step 1425, the codebook corresponding to the firstcodebook mode is used to generate the CSI feedback based on a widebandinter-panel co-phase that is common for a plurality of subbandsconfigured for the CSI feedback. In one embodiment, at step 1425, thecodebook corresponding to the second codebook mode is used to generatethe CSI feedback based on at least one of (i) a wideband inter-panelco-phase that is common for the plurality of subbands, and (ii) asubband inter-panel co-phase for each of the plurality of subbands.

Although the present disclosure has been described with an exemplaryembodiment, various changes and modifications may be suggested to oneskilled in the art. It is intended that the present disclosure encompasssuch changes and modifications as fall within the scope of the appendedclaims.

None of the description in this application should be read as implyingthat any particular element, step, or function is an essential elementthat must be included in the claims scope. The scope of patented subjectmatter is defined only by the claims. Moreover, none of the claims areintended to invoke 35 U.S.C. § 112(f) unless the exact words “means for”are followed by a participle.

What is claimed is:
 1. A user equipment (UE) for channel stateinformation (CSI) feedback, the UE comprising a transceiver configuredto receive, from a base station (BS), configuration information for theCSI feedback, the configuration information indicating a number ofantenna panels (N_(g)) at the BS and a codebook mode, wherein N_(g)>1and each of the antenna panels comprises antenna ports with a firstpolarization (P₁) and antenna ports with a second polarization (P₂); anda processor operably connected to the transceiver, the processorconfigured to: identify the number of antenna panels (N_(g)) at the BS;identify a codebook for the CSI feedback based on the codebook modeconfigured between a first codebook mode and a second codebook mode; andgenerate the CSI feedback using the identified codebook, wherein thetransceiver is further configured to transmit the generated CSI feedbackto the BS, wherein the codebook corresponding to the first codebook modeis used to generate the CSI feedback based on a wideband inter-panelco-phase that is common for a plurality of subbands configured for theCSI feedback, and wherein the codebook corresponding to the secondcodebook mode is used to generate the CSI feedback based on at least oneof (i) a wideband inter-panel co-phase that is common for the pluralityof subbands, and (ii) a subband inter-panel co-phase for each of theplurality of subbands.
 2. The UE of claim 1, wherein: the number ofantenna panels (N_(g)) is two or four, if the number of antenna panelsis two (N_(g)=2), one of the first codebook mode or the second codebookmode is configured, and if the number of antenna panels is four(N_(g)=4), only the first codebook mode is configured.
 3. The UE ofclaim 1, wherein: the number of antenna panels is two (N_(g)=2), thesecond codebook mode is configured, the wideband inter-panel co-phasefor each polarization (P_(i)) of a second of the two antenna panels isgiven by a_(p)=e^(jπ/4)e^(jπp/2), and the subband inter-panel co-phasefor each polarization (P_(i)) of the second antenna panel is given byb_(n)=e^(−jπ/) ^(jπn/2), where p=0,1, 2,3 and n=0,1.
 4. The UE of claim1, wherein: a combination of (N_(g), N₁, N₂), configured via theconfiguration information for the CSI feedback, for a given number ofantenna ports and corresponding values of (O₁, O₂) are determinedaccording to: Number of antenna ports (N_(g), N₁, N₂) (O₁, O₂) 8 (2,2, 1) (4, 1) 16 (2, 4, 1) (4, 1) (4, 2, 1) (4, 1) (2, 2, 2) (4, 4) 32(2, 8, 1) (4, 1) (4, 4, 1) (4, 1) (2, 4, 2) (4, 4) (4, 2, 2)  (4, 4),

N₁ and N₂ respectively are a number of antenna ports with a polarization(P₁ or P₂) in first and second dimensions of each of the antenna panels,and O₁ and O₂ are oversampling factors in the first and seconddimensions, respectively, and N₁, N₂, O₁ and O₂ are used to obtain a setof two-dimensional discrete Fourier transform (DFT) beams, v_(l,m),where l=0,1, . . . , O₁N₁, m=0,1, . . . , O₂N₂, and$u_{m} = \left\{ {{\begin{matrix}\begin{bmatrix}1 & e^{j\frac{2\; \pi \; m}{O_{2}N_{2}}} & \ldots & e^{j\frac{2\pi \; {m{({N_{2} - 1})}}}{O_{2}N_{2}}}\end{bmatrix} & {N_{2} > 1} \\1 & {N_{2} = 1}\end{matrix}v_{l,m}} = {\begin{bmatrix}u_{m} & {e^{j\frac{2\; \pi \; l}{O_{1}N_{1}}}u_{m}} & \ldots & {e^{j\frac{2\pi \; {l{({N_{1} - 1})}}}{O_{1}N_{1}}}u_{m}}\end{bmatrix}^{T}.}} \right.$
 5. The UE of claim 4, wherein: for thefirst codebook mode, the codebook for generating the CSI feedback forN_(g)=2,4 is constructed using vectors:$W_{l,m,p,n}^{1,2,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}}\end{bmatrix},{W_{l,m,p,n}^{2,2,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}}\end{bmatrix},{W_{l,m,p,n}^{1,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix},{W_{l,m,p,n}^{2,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix},{;{{{where}\mspace{14mu} p} = \left\{ {\begin{matrix}p_{1} & {N_{g} = 2} \\\begin{bmatrix}p_{1} & p_{2} & p_{3}\end{bmatrix} & {N_{g} = 4}\end{matrix},{and}} \right.}}}}}}}}}}}}}}}}}$ for the second codebookmode, the codebook for generating the CSI feedback for N_(g)=2 isconstructed using vectors:$W_{l,m,p,n}^{1,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}}\end{bmatrix},{W_{l,m,p,n}^{2,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}}\end{bmatrix},}}}}}}}$ where:p=[p ₁ p ₂]n=[n ₀ n ₁ n ₂]′ n, n₀=0,1,2,3; p₁, p₂, p₃=0,1,2,3; n₁,n₂=0,1; andP_(CSI-RS) is the number of antenna ports, andφ_(n) =e ^(jπn/2)a _(p) =e ^(jπ/4) e ^(jπp/2)b _(n) =e ^(−jπ/4)e^(jπn/2)
 6. The UE of claim 5, wherein: the CSIfeedback includes a pre-coding matrix indicator (PMI) that includes PMIindices i_(1,1), i_(1,2). i_(1,3), i_(1,4), and i₂, for 1-layer CSIfeedback: for the first codebook mode, the codebook comprises pre-codingmatrices: W_(l,m,p,n) ⁽¹⁾=W_(l,m,p,n) ^(1,N) ^(g) ^(,1), and for thesecond codebook mode, the codebook comprises pre-coding matrices:W_(l,m,p,n) ⁽¹⁾=W_(l,m,p,n) ^(1,N) ^(g) ^(,2); for 2-layer CSI feedback:for the first codebook mode, the codebook comprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1}\end{bmatrix}}},$ and for the second codebook mode, the codebookcomprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2}\end{bmatrix}}};$ for 3-layer CSI feedback: for the first codebook mode,the codebook comprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},1} & W_{l,m,p,n}^{2,N_{g},1}\end{bmatrix}}},$ and for the second codebook mode, the codebookcomprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},2} & W_{l,m,p,n}^{2,N_{g},2}\end{bmatrix}}};$ and for 4-layer CSI feedback: for the first codebookmode, the codebook comprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},1} & W_{l,m,p,n}^{2,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1}\end{bmatrix}}},$ and for the second codebook mode, the codebookcomprises pre-coding matrices:$W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},2} & W_{l,m,p,n}^{2,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2}\end{bmatrix}}$ where:l=i _(1,1) , m=i _(1,2) ,l′=i _(1,1) +k ₁ , m′=i _(1,2) +k ₂. for thefirst codebook mode, $p = \left\{ {\begin{matrix}{{p_{1} = {i_{1,4,1} = i_{1,4}}},} & {N_{g} = 2} \\{{\begin{bmatrix}p_{1} & p_{2} & p_{3}\end{bmatrix} = {\begin{bmatrix}i_{1,4,1} & i_{1,4,2} & i_{1,4,3}\end{bmatrix} = i_{1,4}}},} & {N_{g} = 4}\end{matrix},} \right.$ and n=i₂, for the second codebook mode, N_(g)=2,p=[p₁ p₂]=[i_(1,4,1) i_(1,4,2)]=i_(1,4), and n=[n₀ n₁ n₂]=[i_(2,0)i_(2,1) i_(2,2)]=i₂. i_(1,1) and i_(1,2) are PMI indices that indicate afirst beam v_(i) _(1,1) _(,i) _(1,2) _(,) i_(1,3) is a PMI index thatindicates a distance (k₁, k₂) of a second beam v_(i) _(1,1) _(+k) ₁_(,i) _(1,2) _(+k) ₂ with respect to the first beam v_(i) _(1,1) _(,i)_(1,2) _(,) i_(1,4) is a PMI index that indicates the widebandinter-panel co-phase, and i₂ is a PMI index that indicates: for thefirst codebook mode, a subband co-phase between two polarizations iscommon for all of the antenna panels, and for the second codebook mode,the subband co-phase between two polarizations of a first of the antennapanels (via i_(2,0)), and the subband inter-panel co-phase for eachpolarization of a second of the antenna panels (via i_(2,1), i_(2,2)).7. The UE of claim 6, wherein: k₁=0, k₂=0, and i_(1,3) is not includedfor the 1-layer CSI feedback, mapping of i_(1,3) to k₁ and k₂ for the2-layer CSI feedback for N_(g)=2 or 4 is determined according to: N₁ >N₂ > 1 N₁ = N₂ N₁ = 2, N₂ = l N₁ > 2, N₂ = 1 i_(1, 3) k₁ k₂ k₁ k₂ k₁ k₂k₁ k₂ 0 0 0 0 0 0 0 0 0 1  O₁ 0 O₁ 0 O₁ 0  O₁ 0 2 0 O₂ 0 O₂ 2O₁ 0 3 2O₁0 O₁ O₂ 3O₁  0,

and mapping of i_(1,3) to k₁ and k₂ for the 3-layer or 4-layer CSIfeedback for N_(g)=2 or 4 is determined according to: N₁ = 2, N₂ = 1 N₁= 4, N₂ = 1 N₁ = 8, N₂ = 1 N₁ = 2, N₂ = 2 N₁ = 4, N₂ = 2 i_(1, 3) k₁ k₂k₁ k₂ k₁ k₂ k₁ k₂ k₁ k₂ 0 O₁ 0  O₁ 0  O₁ 0 O₁ 0 O₁ 0 1 2O₁ 0 2O₁ 0 0 O₂0 O₂ 2 3O₁ 0 3O₁ 0 O₁ O₂ O₁ O₂ 3 4O₁ 0 2O₁  
 0.


8. A base station (BS), the BS comprising a processor configured togenerate configuration information for channel state information (CSI)feedback, the configuration information indicating a number of antennapanels (N_(g)) at the BS and a codebook mode, the codebook modeindicating a codebook for the CSI feedback and configured between afirst codebook mode and a second codebook mode, wherein N_(g)>1 and eachof the antenna panels comprises antenna ports with a first polarization(P₁) and antenna ports with a second polarization (P₂); and atransceiver operably connected to the processor, the transceiverconfigured to: transmit, to a user equipment (UE), the configurationinformation; and receive the CSI feedback from the UE generated inaccordance with the indicated codebook, wherein the codebookcorresponding to the first codebook mode is used to generate the CSIfeedback based on a wideband inter-panel co-phase that is common for aplurality of subbands configured for the CSI feedback, and wherein thecodebook corresponding to the second codebook mode is used to generatethe CSI feedback based on at least one of (i) a wideband inter-panelco-phase that is common for the plurality of subbands, and (ii) asubband inter-panel co-phase for each of the plurality of subbands. 9.The BS of claim 8, wherein: the number of antenna panels (N_(g)) is twoor four, if the number of antenna panels is two (N_(g)=2), one of thefirst codebook mode or the second codebook mode is configured, and ifthe number of antenna panels is four (N_(g)=4), only the first codebookmode is configured.
 10. The BS of claim 8, wherein: the number ofantenna panels is two (N_(g)=2), the second codebook mode is configured,the wideband inter-panel co-phase for each polarization (P_(i)) of asecond of the two antenna panels is given by a_(p)=e^(jπ/4)e^(jπp/2),and the subband inter-panel co-phase for each polarization (P_(i)) ofthe second antenna panel is given by b_(n)=e^(−jπ/4)e^(jπn/2). wherep=0,1, 2,3 and n=0,1.
 11. The BS of claim 8, wherein: a combination of(N_(g), N₁, N₂), configured via the configuration information for theCSI feedback, for a given number of antenna ports and correspondingvalues of (O₁, O₂) are determined according to: Number of antenna ports(N_(g), N₁, N₂) (O₁, O₂) 8 (2, 2, 1) (4, 1) 16 (2, 4, 1) (4, 1) (4,2, 1) (4, 1) (2, 2, 2) (4, 4) 32 (2, 8, 1) (4, 1) (4, 4, 1) (4, 1) (2,4, 2) (4, 4) (4, 2, 2)  (4, 4),

N₁ and N₂ respectively are a number of antenna ports with a polarization(P₁ or P₂) in first and second dimensions of each of the antenna panels,and O₁ and O₂ are oversampling factors in the first and seconddimensions, respectively, and N₁, N₂, O₁ and O₂ are used to obtain a setof two-dimensional discrete Fourier transform (DFT) beams, v_(l,m),where l=0,1, . . . , O₁N₁, m=0,1, . . . , O₂N₂, and$u_{m} = \left\{ {{\begin{matrix}\begin{bmatrix}1 & e^{j\frac{2\; \pi \; m}{O_{2}N_{2}}} & \ldots & e^{j\frac{2\pi \; {m{({N_{2} - 1})}}}{O_{2}N_{2}}}\end{bmatrix} & {N_{2} > 1} \\1 & {N_{2} = 1}\end{matrix}v_{l,m}} = {\begin{bmatrix}u_{m} & {e^{j\frac{2\; \pi \; l}{O_{1}N_{1}}}u_{m}} & \ldots & {e^{j\frac{2\pi \; {l{({N_{1} - 1})}}}{O_{1}N_{1}}}u_{m}}\end{bmatrix}^{T}.}} \right.$
 12. The BS of claim 11, wherein: for thefirst codebook mode, the codebook for generating the CSI feedback forN_(g)=2,4 is constructed using vectors:$W_{l,m,p,n}^{1,2,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}}\end{bmatrix},{W_{l,m,p,n}^{2,2,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}}\end{bmatrix},{W_{l,m,p,n}^{1,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix},{W_{l,m,p,n}^{2,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix},{;{{{where}\mspace{14mu} p} = \left\{ {\begin{matrix}p_{1} & {N_{g} = 2} \\\begin{bmatrix}p_{1} & p_{2} & p_{3}\end{bmatrix} & {N_{g} = 4}\end{matrix},} \right.}}}}}}}}}}}}}}}}}$ and for the second codebookmode, the codebook for generating the CSI feedback for N_(g)=2 isconstructed using vectors:$W_{l,m,p,n}^{1,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}}\end{bmatrix},{W_{l,m,p,n}^{2,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}{\quad{\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}}\end{bmatrix},}}}}}}}$ where:p=[p ₁ p ₂]n=[n ₀ n ₁ n ₂]′ n, n₀=0,1,2,3 ; p₁, p₂, p₃=0,1,2,3; n₁,n₂=0,1; andP_(CSI-RS) is the number of antenna ports, andφ_(n) =e ^(jπn/2)a _(p) =e ^(jπ/4) e ^(jπp/2)b _(n) =e ^(−jπ/4) e ^(jπn/2)
 13. The BS of claim 12, wherein: the CSIfeedback includes a pre-coding matrix indicator (PMI) that includes PMIindices i_(1,1),i_(1,2)i_(1,3),i_(1,4), and i₂. for 1-layer CSIfeedback: for the first codebook mode, the codebook comprises pre-codingmatrices: W_(l,m,p,n) ⁽¹⁾=W_(l,m,p,n) ^(1,N) ^(g) ^(,1), and for thesecond codebook mode, the codebook comprises pre-coding matrices:W_(l,m,p,n) ⁽¹⁾=W_(l,m,p,n) ^(1,N) ^(g) ^(,2); for 2-layer CSI feedback:for the first codebook mode, the codebook comprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1}\end{bmatrix}}},$ and for the second codebook mode, the codebookcomprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2}\end{bmatrix}}};$ for 3-layer CSI feedback: for the first codebook mode,the codebook comprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},1} & W_{l,m,p,n}^{2,N_{g},1}\end{bmatrix}}},$ and for the second codebook mode, the codebookcomprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},2} & W_{l,m,p,n}^{2,N_{g},2}\end{bmatrix}}};$ and for 4-layer CSI feedback: for the first codebookmode, the codebook comprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}\begin{matrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},1} & W_{l,m,p,n}^{2,N_{g},1}\end{matrix} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1}\end{bmatrix}}},$ and for the second codebook mode, the codebookcomprises pre-coding matrices:$W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}\begin{matrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},2} & W_{l,m,p,n}^{2,N_{g},2}\end{matrix} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2}\end{bmatrix}}$ where:l=i_(1,1,), m=i_(1,2), l′=i_(1,1)+k₁, m′=i_(1,2)+k₂. for the firstcodebook mode, $p = \left\{ {\begin{matrix}{{p_{1} = {i_{1,4,1} = i_{1,4}}},} & {N_{g} = 2} \\{{\begin{bmatrix}p_{1} & p_{2} & p_{3}\end{bmatrix} = {\begin{bmatrix}i_{1,4,1} & i_{1,4,2} & i_{1,4,3}\end{bmatrix} = i_{1,4}}},} & {N_{g} = 4}\end{matrix},} \right.$ and n=i₂, for the second codebook mode, N_(g)=2,p=[p₁ p₂]=[i_(1,4,1) i_(1,4,2)]=i_(1,4), and n=[n₀ n₁ n₂]=[i_(2,0)i_(2,1) i_(2,2)]=i₂. i,_(1,1) and i_(1,2) are PMI indices that indicatea first beam v_(i) _(1,1) _(,i) _(1,2) , i_(1,3) is a PMI index thatindicates a distance (k₁, k₂) of a second beam v_(i) _(1,1)+k₁,i_(1,2)+k₂ with respect to the first beam v_(i) _(1,1) _(,i) _(1,2)_(.) i_(1,4) is a PMI index that indicates the wideband inter-panelco-phase, and i₂ is a PMI index that indicates: for the first codebookmode, a subband co-phase between two polarizations is common for all ofthe antenna panels, and for the second codebook mode, the subbandco-phase between two polarizations of a first of the antenna panels (viai_(2,0)), and the subband inter-panel co-phase for each polarization ofa second of the antenna panels (via i_(2,1), i_(2,2)).
 14. The BS ofclaim 13, wherein: k₁=0, k₂=0, and i_(1,3) is not included for the1-layer CSI feedback, mapping of i_(1,3) to k₁ and k₂ for the 2-layerCSI feedback for N_(g)=2 or 4 is determined according to: N₁ > N₂ > 1 N₁= N₂ N₁ = 2, N₂ = l N₁ > 2, N₂ = 1 i_(1, 3) k₁ k₂ k₁ k₂ k₁ k₂ k₁ k₂ 0 00 0 0 0 0 0 0 1  O₁ 0 O₁ 0 O₁ 0  O₁ 0 2 0 O₂ 0 O₂ 2O₁ 0 3 2O₁ 0 O₁ O₂3O₁  0,

and mapping of i_(1,3) to k₁ and k₂ for the 3-layer or 4-layer CSIfeedback for N_(g)=2 or 4 is determined according to: N₁ = 2, N₂ = 1 N₁= 4, N₂ = 1 N₁ = 8, N₂ = 1 N₁ = 2, N₂ = 2 N₁ = 4, N₂ = 2 i_(1, 3) k₁ k₂k₁ k₂ k₁ k₂ k₁ k₂ k₁ k₂ 0 O₁ 0  O₁ 0  O₁ 0 O₁ 0 O₁ 0 1 2O₁ 0 2O₁ 0 0 O₂0 O₂ 2 3O₁ 0 3O₁ 0 O₁ O₂ O₁ O₂ 3 4O₁ 0 2O₁  
 0.


15. A method for channel state information (CSI) feedback by a userequipment (UE), the method comprising receiving, from a base station(BS), configuration information for the CSI feedback, the configurationinformation indicating a number of antenna panels (N_(g)) at the BS anda codebook mode, wherein N_(g)>1 and each of the antenna panelscomprises antenna ports with a first polarization (P₁) and antenna portswith a second polarization (P₂); identifying the number of antennapanels (N_(g)) at the BS; identifying a codebook for the CSI feedbackbased on the codebook mode configured between a first codebook mode anda second codebook mode; generating the CSI feedback using the identifiedcodebook; and transmitting the generated CSI feedback to the BS, whereinthe codebook corresponding to the first codebook mode is used togenerate the CSI feedback based on a wideband inter-panel co-phase thatis common for a plurality of subbands configured for the CSI feedback,and wherein the codebook corresponding to the second codebook mode isused to generate the CSI feedback based on at least one of (i) awideband inter-panel co-phase that is common for the plurality ofsubbands, and (ii) a subband inter-panel co-phase for each of theplurality of subbands.
 16. The method of claim 15, wherein: the numberof antenna panels (N_(g)) is two or four, if the number of antennapanels is two (N_(g)=2), one of the first codebook mode or the secondcodebook mode is configured, and if the number of antenna panels is four(N_(g)=4), only the first codebook mode is configured.
 17. The method ofclaim 15, wherein: the number of antenna panels is two (N_(g)=2), thesecond codebook mode is configured, the wideband inter-panel co-phasefor each polarization (P_(i)) of a second of the two antenna panels isgiven by a_(p)=e^(jπ/4)e^(jπp/2), and the subband inter-panel co-phasefor each polarization (P_(i)) of the second antenna panel is given byb_(n)=e^(−jπ/4)e^(jπn/2), where p=0,1, 2, 3 and n=0,1.
 18. The method ofclaim 15, wherein: a combination of (N_(g), N₁, N₂), configured via theconfiguration information for the CSI feedback, for a given number ofantenna ports and corresponding values of (O₁, O₂) are determinedaccording to: Number of antenna ports (N_(g), N₁, N₂) (O₁, O₂) 8 (2,2, 1) (4, 1) 16 (2, 4, 1) (4, 1) (4, 2, 1) (4, 1) (2, 2, 2) (4, 4) 32(2, 8, 1) (4, 1) (4, 4, 1) (4, 1) (2, 4, 2) (4, 4) (4, 2, 2)  (4, 4),

N₁ and N₂ respectively are a number of antenna ports with a polarization(P₁ or P₂) in first and second dimensions of each of the antenna panels,and O₁ and O₂ are oversampling factors in the first and seconddimensions, respectively, and N₁, N₂, O₁ and O₂ are used to obtain a setof two-dimensional discrete Fourier transform (DFT) beams, v_(l,m),where l=0,1, . . . , O₁N₁, m=0,1, . . . , O₂N₂, and $\begin{matrix}{u_{m} = \left\{ \begin{matrix}\begin{bmatrix}1 & e^{j\frac{2\; \pi \; m}{O_{2}N_{2}}} & \ldots & e^{j\frac{2\; \pi \; {m{({N_{2} - 1})}}}{O_{2}N_{2}}}\end{bmatrix} & {N_{2} > 1} \\1 & {N_{2} = 1}\end{matrix} \right.} \\{v_{l,m} = \begin{bmatrix}u_{m} & {e^{j\frac{2\; \pi \; l}{O_{1}N_{1}}}u_{m}} & \ldots & {e^{j\frac{2\; \pi \; {l{({N_{1} - 1})}}}{O_{1}N_{1}}}u_{m}}\end{bmatrix}^{T}}\end{matrix}.$
 19. The method of claim 18, wherein: for the firstcodebook mode, the codebook for generating the CSI feedback forN_(g)=2,4 is constructed using vectors: ${\begin{matrix}{{W_{l,m,p,n}^{1,2,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}}\end{bmatrix}}},} & {{W_{l,m,p,n}^{2,2,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}}\end{bmatrix}}},} \\{{W_{l,m,p,n}^{1,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{\phi_{n}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{\phi_{n}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{\phi_{n}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}},} & {{W_{l,m,p,n}^{2,4,1} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n}}v_{l,m}} \\{\phi_{p_{1}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{1}}v_{l,m}} \\{\phi_{p_{2}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{2}}v_{l,m}} \\{\phi_{p_{3}}v_{l,m}} \\{{- \phi_{n}}\phi_{p_{3}}v_{l,m}}\end{bmatrix}}},}\end{matrix};}$$\mspace{20mu} {{{where}\mspace{14mu} p} = \left\{ {\begin{matrix}p_{1} & {N_{g} = 2} \\\begin{bmatrix}p_{1} & p_{2} & p_{3}\end{bmatrix} & {N_{g} = 4}\end{matrix},} \right.}$ and for the second codebook mode, the codebookfor generating the CSI feedback for N_(g)=2 is constructed usingvectors:${W_{l,m,p,n}^{1,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{\phi_{n_{0}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{a_{p_{2}}b_{n_{2}}v_{l,m}}\end{bmatrix}}},{W_{l,m,p,n}^{2,2,2} = {\frac{1}{\sqrt{P_{{CSI} - {RS}}}}\begin{bmatrix}v_{l,m} \\{{- \phi_{n_{0}}}v_{l,m}} \\{a_{p_{1}}b_{n_{1}}v_{l,m}} \\{{- a_{p_{2}}}b_{n_{2}}v_{l,m}}\end{bmatrix}}},$ where:p=[p ₁ p ₂]n=[n ₀ n ₁ n ₂]′ n, n₀=0,1,2,3; p₁, p₂, p₃=0,1,2,3; n₁,n₂=0,1 ; andP_(CSI-RS) is the number of antenna ports, andφ_(n) =e ^(jπn/2)a _(p) =e ^(jπ/4) e ^(jπp/2)b _(n) =e ^(−jπ/4) e ^(jπn/2)
 20. The method of claim 19, wherein: theCSI feedback includes a pre-coding matrix indicator (PMI) that includesPMI indices i_(1,1), i_(1,2), i_(1,3), i_(1,4), and i₂, for 1-layer CSIfeedback: for the first codebook mode, the codebook comprises pre-codingmatrices: W_(l,m,p,n) ⁽¹⁾=W_(l,m,p,n) ^(1,N) ^(g) ^(,1), and for thesecond codebook mode, the codebook comprises pre-coding matrices:W_(l,m,p,n) ⁽¹⁾=W_(l,m,p,n) ^(1,N) ^(g) ^(,2); for 2-layer CSI feedback:for the first codebook mode, the codebook comprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1}\end{bmatrix}}},$ and for the second codebook mode, the codebookcomprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(2)} = {\frac{1}{\sqrt{2}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2}\end{bmatrix}}};$ for 3-layer CSI feedback: for the first codebook mode,the codebook comprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},1} & W_{l,m,p,n}^{2,N_{g},1}\end{bmatrix}}},$ and for the second codebook mode, the codebookcomprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(3)} = {\frac{1}{\sqrt{3}}\begin{bmatrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},2} & W_{l,m,p,n}^{2,N_{g},2}\end{bmatrix}}};$ and for 4-layer CSI feedback: for the first codebookmode, the codebook comprises pre-coding matrices:${W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}\begin{matrix}W_{l,m,p,n}^{1,N_{g},1} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},1} & W_{l,m,p,n}^{2,N_{g},1}\end{matrix} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},1}\end{bmatrix}}},$ and for the second codebook mode, the codebookcomprises pre-coding matrices:$W_{l,l^{\prime},m,m^{\prime},p,n}^{(4)} = {\frac{1}{\sqrt{4}}\begin{bmatrix}\begin{matrix}W_{l,m,p,n}^{1,N_{g},2} & W_{l^{\prime},m^{\prime},p,n}^{1,N_{g},2} & W_{l,m,p,n}^{2,N_{g},2}\end{matrix} & W_{l^{\prime},m^{\prime},p,n}^{2,N_{g},2}\end{bmatrix}}$ where:l=i _(1,1) ,m=i _(1,2) ,l′=i _(1,1) +k ₁ ,m′=i _(1,2) +k ₂, for thefirst codebook mode, $p = \left\{ {\begin{matrix}{{p_{1} = {i_{1,4,1} = i_{1,4}}},} & {N_{g} = 2} \\{{\begin{bmatrix}p_{1} & p_{2} & p_{3}\end{bmatrix} = {\begin{bmatrix}i_{1,4,1} & i_{1,4,2`} & i_{1,4,3}\end{bmatrix} = i_{1,4}}},} & {N_{g} = 4}\end{matrix},} \right.$ and n=i₂, for the second codebook mode, N_(g)=2,p=[p₁ p₂]=[i_(1,4,1) i_(1,4,2)]=i_(1,4), and n=[n₀ n₁ n₂]=[i_(2,0)i_(2,1) i_(2,2)]=i₂, i_(1,1) and i_(1,2) are PMI indices that indicate afirst beam v_(i) _(1,1) _(,i) _(1,2) , i_(1,3) is a PMI index thatindicates a distance (k₁, k₂) of a second beam v_(i) _(1,1) _(+k) ₁_(,i) _(1,2) _(+k) ₂ with respect to the first beam v_(i) _(1,1) _(,i)_(1,2) , i_(1,4) is a PMI index that indicates the wideband inter-panelco-phase, and i₂ is a PMI index that indicates: for the first codebookmode, a subband co-phase between two polarizations is common for all ofthe antenna panels, and for the second codebook mode, the subbandco-phase between two polarizations of a first of the antenna panels (viai_(2,0)), and the subband inter-panel co-phase for each polarization asecond of the antenna panels (via i_(2,1), i_(2,2)).